DIY WORKSHOP

  

Turn Table Victor QL-Y55F

my audio set.jpg

The photo shows the audio-visual equipment in our living room. The turn table on the rack on this side is Victor QL-Y55F.
I wanted my turn table to meet at least the following two condidions.
1. A good wow and flutter attribute(Natural!)
2. Automatic stop
Why 1: For instance, that long non-wavering rendering of a string in symphony No. 8 “Unfinished” by Schubert must be playbacked without deviation. I recognized the importance of such an attribute after ignorantly using a cheap turn table.
Why 2: As I often fall asleep while listening to music, I need a turn table that stops by itself when the stylus comes to the end of a phonograph record.

-1/9-

philips turn table.jpg

(The player in the photo is an old Philips player which Mr. K, a neighbor, gave to me. I cleaned and beautified it and used it for a while. However, it's a manual player and, naturally, doesn't stop automatically. If you don't stop it, the stylus goes on scraping the groove as well as shortening itself. I, as a pensioner, feel such frictional wear my heart.)
So, looking for one, I happened to meet a Victor QL-Y55F at Yahoo auction at that time. I learned it was an ambitious model equiped with a very unique tone arm controlling mechanism. I fell in love with it.
I outbid it as a trouble free player but, unfortunately, it wasn't. But the auctioneer was a good man and the negotiations ended with a satisfactory solution. I got it for a reasonable price as a junk.
Luckily, I could repair the troubles it had at first as well as those it suffered later. It has been playing an important role in my music life.

-2/9-

inside.jpg

The original troubles were:
1. Powere switch failure (It worked sometimes.)
2. Turn table switch failure (It worked sometimes.)
3. Strong stylus pressure and tracking force adjusting volumes failure...
I didn't have any clear prospect of successful repair but anyhow I started dismantling.
Luckily, the electric board was composed with darlington circuits and spacious enough for me to trace them. On top of it, the motor and its controller was healthy.

Details: 1&2. Troubles were caused by cupper rust, carbon and mold thickly accumulated inside the tact switches. I cleaned them with CAIG and they revived. 3. The trouble was caused by mal function of variable resistors. I opened them and cleaned them with CAIG and they revived.
I bought necessary parts ready to replace them for the further troubles.

-3/9-

sw board.jpg

The followings are how I repaired the table.
The sub board, on which are mounted variable resistors for adjusting stylus pressure and traceability, is being detatched.
Another sub board, on which are mounted switches other than power switch, is seen behind.
You can see how this player is spacious enough inside for repair, which can never be possible with those recent digital epuipmenet.
I know it isn't usual but I opened the tact switches to pieces and cleaned them.

-4/9-

cleaning before after.jpg

Left: before cleaning
Right: after cleaning
Such switches can't be taken to pieces again. You have to replace them with the new next time. The same is true with the variable resistors.

-5/9-

.jpg

Upper Left: Push buttn.
Upper Right: Lid.
Below: Disc spring that shorts contact points when pressed. It is completely covered by black things(carbon?).

-6/9-

sw under cleaning.jpg

I scraped off the black surface of the disc spring. It revived OK, but that way of cleaning was not good as it became thinner and it became weak. It lost the original feeling when pressed.
I did the same to the variable resistors and they revived, too.

-7/9-

power section.jpg

The photo shows the power section. You can see a nostalgic hybrid IC.

The cleaning of the switches and variable resistors revived the turn table. However, to get it restored much younger, I replaced all the chemical condensers with the new.
Such are the repair initially done.

-8/9-

Postscript
About one year later, the tone arm lost its normal motion. There are some trimmers(potentiometers) that concern the tone arm control. I marked the trimming position of each trimmer for setting it back and carefully re-adjusted them and, luckily, the arm revived.
Amazingly, the controller of the table revolution has been quite healthy for its age. I thank these Victor engineers for making such wonderful mechanism!
Details (in Japanese) are at Footprint of Audio "Victor Player QL-Y55F"

-9/9-

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EV Speakers and Yamaha Cabinets

buffle inside.jpg

They were married off to me from an acquaintace of mine arranged by Mr.L who had strongly recommended them to me.
The photo shows the original inside except the wiring for a multi-amp driving.
The woofer, two phones and networks were of Electro Voice.
I listened to the sound of this set for a while and judged that they need some improvement. The sound was flabby.
The way the two phones were fixed was unreasonable, too.

-1/9-

buffle rib installed.jpg

To begin with the improvement, I added a rib across the baffle as shown in the photo. It ended without any particular effects.
Next, I replaced 8HDs with JBL horns (2730horn + 2426driver). The mid range sound, naturally, improved but not the bass sound.

-2/9-

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Next, I added center ribs on both side panels and the back panel, and connected them as shown in the upper photo.
Some improvement appeared but the bass sound was still flabby and was lacking that strength a 15-inch caliber woofer usually had.

-3/9-

buffle reformed.jpg

I made up my mind to revam the baffles and install mid range horns inside cabinets. The photo shows the baffle sandwiched with new plywood, and new holes made for fitting horns. The black part is untouched.

-4/9-

reformed with sp15a inside.jpg

The horns and the woofer were installed in vertical line. The baffle became much heavier.
The tweeter was fitted between the mid range horn and the woofer because of the original holes.

-5/9-

.jpg

The photo shows a front look of the reformed speaker, which I stopped driving with multi amps but with a single amp. I also installed new restored networks which I had taken out from SB-7, the old Technics speakers.
Sound improved a lot but not fully satisfactry with its bass sound.

-6/9-

radian2216 installed.jpg

About that time, the back unloaded horn speakers were completed and their sound turned out to be very satisfactory, which almost made me give up renovating these big space occupying speakers.
I was sure that cabinets and horns were okay. That is, I had come to the last step of the renovation. The woofers(Electro Voice SP15) had to be replaced!
The price of a new 15-inch woofer is naturally too expensive. So I looked for a pair of secondhand woofers. JBL woofers, even secondhand, were still too expensive.
After all, I came across a pair of secondhand Radian2216 and I got them for a reasonable price. They were rather new as they had been through with breaking in. Their corns were still glossy.
The long journey of improvement was rewarded. The bass sound, though characteristic of bass reflex speakers, was satisfactry both in quality and ampleness. Data
● Network Crossover frequency: 800Hz、6000Hz
● Tweeter:EV T350 3.5kHz~15kHz ±3dB
● JBLHorn:800 Hz~20 kHz response
● Woofer:Radian2216 40~3.5kHz voice coild iameter 10.5cm           

-7/9-

scrapping1.jpg

Scrapping (added 2017/07/18)
The speaker units were all moved to Nautilus D.I.Y Version and the cabinets became empty. I had to deal with them. They were considerably big, old and useless. I decided to scrap them.
In scrapping, I first took off the glass wool. It was stapled. Taking it off was a prickly work. I packed it in plastic bags to be collected as noninflammable garbage.
The rib and the connection bar in the center were what I added as sound improving measures. However, what actually worked seemed to have been improving the the baffle boards and employing new woofers.

-8/9-

scrapping2.jpg

I learned how to scrap with the first one. Cutting it in two as shown in the photo was a better way.
Taking off staples and screws before cutting were troublesome. I cut some staples with a buzz saw as I made a few oversight of staples.
The scrapping took almost a whole day. I worked overtime that day until sunset. My overtime pay was a canned beer which I shared with my wife.

-9/9-

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Pioneer FM/AM Tuner TX-6300

tx6300 before m.jpg

In order to listen to live recorded music in NHK FM in my living room, I connected a portable audio player or a radio to the amp but the sound was not good.
I found the sound of my old pioneer tuner, TX-6300, was good! It was covered with dust and has been roughly handled long time like a junk in my workshop.
I apologized it for my treatment and decided to use it in my living room. The followings are the record of my atonement.

-1/10-

tx6300 before inside m.jpg

Upper view inside:
I opened it for the first time since I bought it.
Inside was very sparse perhaps because the size was arranged to match other lined up products.
It was unexpectedly clean inside and parts and the mechanism looked very healthy, too.
I listed up the chemical condencers for the later replacement.

-2/10-

tx6300 back inside m.jpg

Bottom view inside:
It's out of sequence but before dismantling, I searched for a service manual in preparation for the later readjustment of FM front end. No Japanese manual seemed available but I found an English manual of TX-5300. The model number is defferent but somehow the outlook and the arrangement of parts are quite the same.
You can get it at http://www.manualslib.com/manual/911336/Pioneer-Tx-5300.html.
I got the manual but rearrangement was unneccessary. There was no tuning gap nor deterioration of sensitivity. I didn't touch the MPX circuit as I haven't needed equipment.
I would replace chemical condensers later but the sound seems very good as it is.

-3/10-

tx6300 before front m.jpg

Upper-front veiw with the panel and dial glass detached:
The rubber fittings for the dial galss were weathered but the printed letters on the glass were not injured. They looked very sturdy and beautiful.
The needle, when tuned to a station, was about 2mm off to the left from the position it ought to be and I adjusted it.

-4/10-

tx6300 panel washed m.jpg

The front panel and the dial glass and a fitting being dried after they were washed:
The aluminum panel seemed applied with clear vanish and it was partly damaged but I decided not to beautify it more.
It was worth washing the dial glass. It became very clean and, with the original lamps, makes a beautiful illuminated visage.
It is not remote controlled but it is not needed as I listen to one particular station.

-5/10-

tx6300 rebuilt2 m.jpg

In listening to FM broadcast, the radio wave must be stronger enough than the noise.
In order to satisfy this condition, I used a antenna terminal for TV. A wire antenna I installed in the curtain box in the living room was not good.
Later, as the condensers I ordered arrived, I replaced all the old chemical condensers on the boards except those fitted on the lands of IC pins. I decided not to replace them with the new to avoid risks of destroying ICs. For, you can't change condensers without heating a pin with a soldering iron as you take one off and solder a new one there.
The change of condensers, to my disappointment, didn't make any notable improvement in sound. I happened to listen to the sound of Japanese drums, which I could enjoy listening to very comfortably.
TX-6300 was produced in about 1975. It has survived longer than 40 years. Isn't it amazing!

-6/10-

booster making.jpg

Installing a booster:
Later, I wanted to boost the output power a little and told it to Mr. H. He sent me a circuit of 5-power booster within the day, with telling that he had ordered necessary parts, too (big thanks!).
The photo shows the booster being made. I put parts on to a small piece of board I happened to have at hand.

-7/10-

booster installed.jpg

I installed the booster with convenient screws on the main board. I warried about the noise in vain.

-8/10-

volume installed.jpg

It turned out that the 5-power boodter was too powerful and so I installed volumes to adjust the input level.

-9/10-

Post script
FM broadcast extends the world of music beyond your expectation. There are two big advantages in being able to listen to FM broadcasts as follows. 1. You can get the most ap-to-date information and knowledge about music.
2. FM broadcasts more HiFi music. I have found the live performance in front of the microphone at the studio is most HiFi, and the live recorded performance, like those music in the N-kyo(NHK Symphony Orchestra, Tokyo) hours comes next. I judge it's hard for CD music to match them.

-10/10-

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Condenser Tuning Of Tube Amps

Condenser Tuning Refined2 Added (2018/07/19) here
Condenser Tuning Refined Added (2018/06/28)here

Preface
I did a condenser tuning to my 6N6P A-class differencial push-pull amp which was designed and its parts prepared by Mr. Perch. I was not fully satisfied with its sound in that it lacked punch a little.
With the tuning the sound became punchier yet delicate.
A condenser tuning is a method of improving performance of an equipmeent or machinery. It was once a popular topic of car tuning among young men. The cars then with mechanical distributors were handy targets of analog tuning.
Such tuning that lacks scientific proof was, is and will be looked coldly on by learned engineers.
As I am a do-it-yourselfer to whom all's well that ends well, I don't mind if something isn't scientifically explained. This time I surely recognized the effect of the condenser tuning and therefore report here how I did it.

-1/11-

condenser added.jpg

The three horizontally attached sylindrical objects are the condensers. There are more condensers attached inside too.
Their capacity/withstand voltage are all 100μF/450V.
I used old condensers I had and that is why they are so big for their capacity. They can be replaced by one much smaller condenser.

-2/11-

perche.jpg

An outlook of the original 6N6P amp.

-3/11-

circuit with condensers.jpg

The circuit above shows where condensers are added as rectangle 1, 2 and 3.
Rectangle 1: resistor 0.3Ω, chemicon 630μF/450V, filmcon10μF/400V
Rectangle 2 : resistor 0.3Ω, chemicon 220μF/350V, filmcon20μF/400V
Rectangle 3: filmcon 10μF/400V(pararell to original chemicon 470μF/50V)
Rectangle 3 is the power supply to the first stage amplifier with FET 2SK30Y.
Film condensers are added parallel to each chemical condenser for more delicate and graceful expression of strings.

-4/11-

condensers inside.jpg

An inside photo of the shassis. Red circles show where condensers or resistors were added.
From left to right
The resistor 0.3Ω in rectangle 2
The condensers in rectangle 2
The film condenser in rectangle 3
The condensers and the resistor 0.3Ω in rectangle 1

-5/11-

6n6p without con 3khz b plus and output.jpg

The waveforms on an oscilloscope before tuning.
The B+ of an A-class amp ought to be fixed but actually it is fluctuating synchronized with that of the output.
The blue waveform represents the fluctuations on B+. The maximum fluctuation value is some 20mV.
The red waveform monitors maximum output without distortion.
You can read one cycle of the red waveform corresponds with two cycles of the blue waveform.
I conjecture the latter corresponds with the fluctuation of the voltage at the center of two 3.3Ω resistors between the 6N6P cathodes.
I'll put up an oscilloscope picture at the bottom in order to show a basis of my conjecture.

-6/11-

6n6p with con 3khz b plus and output.jpg

The photo above shows waves after condensers were attached.
The maximum fluctuation value on the blue waveform can be read to be some 10mV. The improvement is 6db. No changes are found on the red wave.
For the first time in my life I witnessed the wave forms that represent sound improvement. It is very exciting to find and observe the real values and waves.

-7/11-

6n6p without con 7khz 50μs c of athodes.jpg

The waveforms that were monitored at an output and at the center of two 3.3Ω resistors between 6N6P cathodes.
The blue waveform monitors the fluctuation of voltage between the two cathodes.
The red waveform monitors the fluctuation of voltage at an output.
I conjecture that the uneven peakes in the red waveform here are reflected in the blue uneven waveforms above.

-8/11-

Review
This tuning brought the improvement of the B+ regulation by some 10mV. Counting the value of 190V of the B+ voltage the rate of improvement is only about 0.005%. Could it be called improvement? It is far less a value from the bodily sensed effect of the tuning.
At any rate the result was very satistactory and I did the same tuning to other three amps I had built. Their sound became all punchier yet delicate.

What were brought are as follows:
1. Re-balancing the current between the final tubes needed.
2. The sound volume of the higher range as well as that of the lower range increased.
3. The sound of the higher range became so strong that I had to attenuate it. Yet they are still delicate and graceful.

N.B.
There are changes and improvements as above but no change is found on the maximum wave forms. This phenomenon taken into account with the fact of the increase of the sound volume concludes the condenser tuning brings increase of the total output energy.

-9/11-

Postscript
I was repeatedly listening to Beethoven's symphonies no.3 and no.8 conducted by Paavo Jarvis and also Paganini's violin concerto played by Nemanja Radulovic just before this tuning. Punch is characteristic of these music. So I was using the 6CA7 amp as the sound of 6N6P amp was a little unsatisfactory. The 6CA7 amp was already added with big condensers only right next to rectifiers though.
After the tuning the sound of 6N6P amp improved a lot. Encouraged I did the same tuning to other three amps including the 6CA7 amp.
Tunings were all successful. The improvement of 71A amp was most obvious as its sound was beautiful but slender.(to be continued)

-10/11-

(continued)
I had underestimated the sound of CDs but it was my amps that were responsible. The sound improved as if our CDs all became SACDs. The sound of David Oistrakh's violin is really touching and now I can listen to the music of Bach, which I couldn't enjoy before.
6N6P amp became almighty for any music and it is now unnecessary to change amps to 6CA7 amp, the most powerful one among the amps I have. However the result is very cynical. Now I don't need any amps other than 6N6P amp.

-11/11-

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Condenser Tuning Refined (2018/06/28)
condenser tuning refined2.jpg

There were three must be improved points that had been left untouched as to the last condenser tuning. I could finally implement the following improvements.
1.Replacing old condensers with new and smaller but of more capacity ones.
2.Removing the condensers from inside the chassis to the outside.
3.Isolating the condensers next to the FET ripple filter attempting to make the power more independently regulated on each channel.

The photo shows the finished view of the amp with newly arranged condensers. All the added condensers except one film condenser for the first stage FET amplifiers were placed on the print board outside the shassis. Their sizes were all almost the same accidentally. Red ones are film condensers attached parallel to black chemi-cons each nearby.

―1 of added 2 ―

condenser tuned power section.jpg

The photo is the circut of the power section.
I used wire wound resistors next to the rectifiers and the FET ripple filter expecting their inductances would help prevent destruction of semiconductors from inrush current.
The condensers next to the FET ripple filter are separately grouped through separate resistors. No oscillographic difference was found but the sound was of more three-dimensional.
The dumping factor, by way of the ON-OFF method, was about 4. Unfortunately I have no numerical value to compare with as I didn't check it before tuning. My calculation of the factor of the very first original Perche 6N6P amp turned out to be about 3.35, just for an information.

―2 of added 2―

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Condenser Tuning Refined2 (2018/07/19)
condenser tuning refined2.jpg

The successful refining of the previous amp drove me to another refining/reforming of the 6DJ8+6N6P amp.
The reformed amp is placed on the lower rack in the photo above while it was auditioned.
The renovation was two staged. The first was to replace 6DJ8s with FETs. I had been worrying for a long time the unstable behavior of 6DJ8s. The second is the refining of the condenser tuning.
The replacing 6DJ8s with FETs were successful. I'm now completely free from the worry.
The condensers were placed out on the chassis at the positions where there were tubes before and their capacities increased as well as they were divided into two groups by way of resistors(inrush current protectors) to supply power separately to right and left channels.

―1 of 4 of added2―

condenser tuned power section.jpg

The photo above is a backside view of the shassis within which are installed two small circuit boards that replaced tubes. Each of them(the first stage amplifiers) is composed of two 2SK117GRs, one 2SK30A and four resistors.

―2 of 4 of added2―


The photo is an upper view of the renovated amp. There are three aluminum heat insulators I installed in order to protect condensers from the tube heat.

condenser tuned power section.jpg

I set NFB to 6db. The dumping factor turned out to be ≒2.8.
The internal resistance turned out to be ≒2.8 too.
The B+ voltage regulation was 6mV. That is, the total improvement of the regulation turned out to 10.5db.
Data were taken under the same conditions as they were taken for the previous amp.

―3 of 4 of added2―


Circuit of the condenser tuned power section

condenser tuned power section2.jpg

Review:
Refining of the condenser tuning resulted in a sort of natural reality. That is, the amp reproduced the very same sound as that of the previous amp, not something superb I had romantically dreamt of. However, the regulation of B+ power this time improved to 6mV, which brought the volume nob setting a few more degrees backward. That is, this condenser tuning brought more increase of the total output energy.

―4 of 4 of added2―

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Nautilus D.I.Y.
Network Connector Renewal
(Installed on 2019/04/19)

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As malcontact had become more often and worse I replaced connectors of the speaker networks on the Nautilus D.I.Y. The photo shows the networks with the new connectors mounted. They were the networks originally used on Technics SB-7 System.
The boards are different in color betraying, I suppose, a situation of the subcontracted work in those days. I had once found very different sized condensers of the same capacity.

―1/5―

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The old pins were like this. They were built stout but their surface had lost the original conduction.

―2/5―

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The photo shows an original housing, a pin and a socket and a home made socket detaching tool. The tool I made with a nail the tip of which is hardened. It proved itself to be very useful.
I have learned that on the surface of metal a thin but very hard non-conductive invisible layer is formed due to aging. It regists against burnishing.

―3/5―

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The photo shows newly installed 4-pin and 3-pin bases as originals were with a kind of adapter made of lug terminals. The new connectors are more reliable than the old ones as the pins and sockets contact more tight structurally.

―4/5―

speaker connector renewal/images/reformed network installed.jpg

The renewed network boards were installed back as in the photo where a 5-pin connector is showing.
The connector renewal revived the system. The volume efficiency it had been losing for BUHSP1 was restored proving the old connectors were wasting the sound power.

―5/5―

Appendix


improved crimp pliers.jpg

Assembling new connector housings was very difficult taking me one full day because I did it by the side of speakers where wire harnesses were, plus my crimping pliers were too big. The photo shows how I renovated the pliers. I fixed a thin metal piece in order to make the gap narrower.

―5/6―


  

Network Cases For Nautilus D.I.Y.

Installed on 2020/10/15
1 network cases finished.jpg

I have finally made cases for the network devices of Nautilus D.I.Y. The job was a long-pending matter. I made them with leftover materials as I have been doing these days. I had postponed making them because they had nothing to do with sound. However, the ugly look behind the baffle boards had caused me pain ever since I made the system.

―1/6―

2 revised network installed.jpg

I made the cover with a piece of transparent material. It helps the appearance behind the board look smart. The network encased, dusting will be easier, too.

―2/6―

3 behind baffle board.jpg

The photo shows the look without network devices. White spots show the old screw holes stuffed with putty. I have moved the horn slings too in order not to meddle with the case.

―3/6―

4 revised network.jpg

The photo shows the network with the supplimentary circuit that are encased with. I newly made the circuit in order to lower the voltage to the mid-range horn. As I couldn't get non-inductive resisters I connected two resisters parallel in reversed direction. How does the idea work? I don't know. It may not be necessary.

―4/6―

5 circuit breaker.jpg

These are the circuit breakers taken away this time. They had been installed in ordr to protect the voice coils from burning with too much currency onto the mid-range and hi-range horns. They got too old and lost the function. I can do without them as my amplifiers are smaller and safe enough for the coils.

―5/6―

6 network before and after.jpg

The photos show the old and the new appearances behind the baffle. The lower half is reddish by the strong reflection of the case which is painted red as I took the photo on a very bright sunny day.
Good appearance brings better sound too!?

―6/6―

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Fixing Attenuator Shafts


(Installed on 2021/02/11)

1-made it longer.jpg
The shaft of the attenuator to a tweeter of Nautilus DIY broke. The photo above shows the shaft beeing fixed with a piece of coil spring.
It had been lengthened to meet the thick baffle board. I knew it was fragile. It took a few days before I came to the idea of fixing it with a piece of coil spring I had kept. I had bought some pull coil sprigs when I made the pots and pans hook board.

―1/5―

2-broken shaft.jpg
The lengtheded shaft broke as shown in the photo above. I had lengthened the shaft with a piece of brass pipe as thick as the shaft. It had been fastened with a piece of copper wire as well as glued to the shaft tip. It was fragile I knew.

―2/5―

 
3-not broken long shaft.jpg
The photo shows the attenuator to the mid-range horn, the shaft of which is not broken but I repaired it likewise taking this opportunity.

―3/5―

4-how made it longer.jpg
The specification of the coil spring I used were: 0.5mm×5.5mm×35mm. That is the inside diameter was 4.5mm against the 6mm outside diameter of the shaft. Putting the coil on to the shaft was very difficult. I did it by putting it one turn after one turn, sliding each turn very little at a time. It was the only possible way I found. It challenged my eye sight as well as the durability of my finger tip.
However, the lengthened shaft was very stout. Also, I learned the coil piece needed was only the half of what I used, which I applied to the next one.

―4/5―

5-attenuator re-installed.jpg

The attenuator was installed to the baffle board as shown in the photo. It turned out that the lengthened shaft was stout enough to be handled without any special attention. Incidentally I checked the attenuators on the other channel. I judged their shafts don't need repair this time.

―5/5―
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Sony DHC-MD373
Fixing CD Tray


(Installed on 2021/05/02)

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SD-GX1-B by Sharp, the amplifier in our dining room, had shown the decline of output power. While we got by chance a Sony DHC-MD373 and we replaced the former with it. The latter seemed normal with regard to the output power but unfortunately it had the CD tray trouble and I tried to fix it. Luckily, I could successfully repair it. The repair this time was challenging in taking the CD tray component into pieces and making a substitute belt.

―1/10―

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Repair work of one thing is always followed by its cleaning to begin with. The amp was full of dust inside. So I cleaned the amp first with a painting blush, a duster spray and a vacuum cleaner.

―2/10―

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At some places inside the chassis formed rust and I treated them with a rust preventive. It seemed water had been spilt. Luckily the circuit boards and the transformer were safe.

―3/10―

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CD tray function trouble was caused by the loss of the belt. I found it melted and accumulated under the motor pulley. I tried to remove the debris but I couldn't. It was sticky and the place was secluded. The component needed to be taken out and put into pieces for the perfect cleaning.

―4/10―

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There were well thought-out challenging devices you had to learn before taking off the component.
The slit disk, as shown in the photo, could be taken out their three fins pushed out one by one through the notch on its holder.

―5/10―

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The CD tray can be taken off by setting down two latches. They are invisible, showing themselves only when the tray is out.
As shown in the photo the latch in the white circle can be set down by pushing the rod behind the latch leftward, and the other latch in the small yellow circle can be released by pushing the tongue in the larger circle as it stays above it. They are both one way latches and you can put the tray back to its place only by sliding it in. The latches clap and the tray is set.

―6/10―

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I could clean off the tar like debris as shown in the photo.

―7/10―

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I made a ring for the belt from a piece of rubber sheet the thickness of which was 0.5mm. The inner diameter was about 35mm with about 1.5mm width. I used a rotation cutter for woodwork the edge of which was dull. So I neatly sharpened it for precise rubber cuttig and made a temporary cutting bed applying double-sided adhesive tape on which was fixed the rubber sheet.
A piece of thick nylon or polypropylene thread I tried turned out to be unsuitable for the belt as neither of them lacked elasticity.

―8/10―

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The belt was installed as shown in the photo.
Incidentally, a yellowish protruding thing beside the motor pulley is a switch lever that is pushed to function as the tray slides inside or outside all the way. It cuts the power as well as changes + or - alternately for the next slide. The cogwheel unit swings 90 degrees outward around the axis of the pulley in order to fix the tray at the innermost position. Well designed mechanism!!

―9/10―

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The repair was successful. A CD was set or ejected as the eject button was pressed. Incidentally I cleaned the surface of the optical lens before reassembling. A thin film had formed on it.

―10/10―
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Fixing Sharp SD-GX1-B


(Installed on 2021/05/11)

1-repaired and revived sharp.jpg
Our SD-GX1-B by Sharp had a symptom of lowering output power. The model was up for sale first in 2003. I surmised the power condensers had lost their capacity. I replaced them with new ones, which brought back the original well-rounded sound. We had accustomed to the skinny sound unnoticed. Incidentally I repladed a damaged ribbon feeder on this repair occasion.
The Photo shows the SD-GX1-B which was placed back to our dining room again replacing the remote controller lacking DHC-MD373. I'm now planning to do the same repair to the latter.

―1/11―

2-tape unit on upper case.jpg
The photo shows the inside of the upper cover on which was installed a cassette tape player unit. The two driving belts were badly worn, one of which beeing almost melted. I took them off as I didn't plan to use cassette tapes.

―2/11―

3-upper case front panel taken off.jpg
On the metal bottom plate were installed the CD unit, MD unit, the power units and the main circuit board. The tuner unit was installed on the back panel. They were connected with ribbon cables or flat cables, which you had to treat carefully when disconnecting.

―3/11―

4-cd stabilizer.jpg
The CD stabilizer was detatchable upward using notches on the plastic disk.

―4/11―

5-tray put on take off latches s.jpg
The one-way CD tray setting(taking off) mechanism used two devices. One was the supple plastic bar in the right yellow circle and the other the metal spring in the left circle. No rubber belts were used, which I liked very much. They are short-lived.

―/11―

6-optical lens cleaned.jpg
Taking off the CD stabilizer and the tray you could access the optical lens. A thin semitransparent film formed on the surface. I cleaned it but it turned out later that the unit often failed to reat cd-r disks. It seemed the optical unit had other deterioration.

―6/11―

7-damaged ribbon cable.jpg
The photo shows a damaged ribbon cable on the display board which was installed on the front panel. It was not long enough for me to take it off the main circuit board. The damage grew through the past repeated dismantlings.

―7/11―

8-new ribbon cable fixed.jpg
I replaced the cable with a new longer one. Now the panel can be dismantled safely, I don't plan to do it though.

―8/11―

9-power condensers taken off.jpg
I took off the old condensers from the power circuit board proceeding the work cautiously not to damage diodes with the soldering heat. The yellow circles in the photo show the four pairs of lands for the condensers.

―9/11―

10-new condensers installed.jpg
The photo shows the new condensers on the power circuit board.

―10/11―

11-front view.jpg
The SD-GX1-B was reassembled as shown in the photo. You feel anxious at this stage if you had damaged any functions while repairing. Luckily the repair was safe, and was rewarding too. Changing the condensers in order to bring back powerful sound was right, and it brought the quality of the sound besides.

―11/11―
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Kawa Ace N3-256SH (Kawamoto Pump)

       ● Additional Repair 2 as of 2022/06/03 (on sensor board, sensor lever, diaphragm) added
● Additional Repair 1 as of 2021/09/23 (on photo-interruptor) added
● Additional Repair as of 2017/08/19 (on power unit) added
**********************************************

Fine Sensor Repair(Nov.2016)
Preface
Our house when built was located on the outskirt of a village where the water pressure was lower. In order to apply more pressure, we installed a pump with a tank N3-256SH made by Kawamoto Pump. The pump has been used for nearly thirty years. See also Ball Tap Link
However, it seems to have gotten old and began to fail in getting started. Luckily I could repair it.

-1/24-

house inside overview.jpg

The pump is controlled by two sensing switches.
It starts when a pressure sensor detects the decompression of water.
It stops when a flow sensor detects the stop of water flow.
The red circle shows the photo switch which senses the water pressure.
The cover comes off as you pull it with force. Then you can approach screws for taking off the unit. A slender plus driver is recomended for the work.

-2/24-

fine sensor inside.jpg

The photo sensor is soldered downward on to the print board, by the side of which is installed the interrupter adjuster with a screw and a coil spring.

-3/24-

fine sensor disassembled.jpg

The red circle shows the photo sensor switch.
The navy blue circle shows the intercepting lever that moves on and off the optical path.
The trouble was caused by a kind of insect nest at the photo sensor slit. By cleaning the slit the sensor revived.
The photo was taken after cleaning.

-4/24-

photo interrupter illustrated.jpg

The illustration, which I downroaded from Roam, shows the structure of a photo sensor switch. Roam calls it a photo interrupter.

-5/24-

gp1a52hrj00f_e.jpg

This illustartion shows the equibalent circuit of the device(photo-interrupter) which was actually used in the sensor.
GP1A52HRJ00F is a SHARP device the intercepted output level of which is low.

-6/24-

Power Supply Repair (August 19, 2017)
It started to happen that water from a faucet suddenly stops or water doesn't come out of a faucet when opened. These malfunctions automatically recovered after a few minutes each time but they irregularly happened and never stopped.
I checked the sensor unit but there was no bug nest. The sensor might have deteriorated I thought and I neatly cleaned the surfaces of the optical path. It didn't work.

-7/24-

controller opened.jpg

As I mentioned before, the pump has been working for more than 30years. It may have done its term of service.
However, the motor is still beautifull and the pump functions quite normal when it works.
So I opened the black plastic box (at the center of the photo) hoping to find any other cause, not mechanical but electrical.

-8/24-

condensers on board.jpg

I surmised there, on the board, are a power supply section with a transformer of 15V output and a switching section with a semiconductor installed on to the box with a piece of heat sink tissue.
I paid my attention to three chemical condensers in the power supply section. (They are yellow circled in the photo.) It was very probable they were deteriorated. The life of chemical condensers are rather short.
So, I replaced them with new ones.
The pump revived and started to work normally. My assumption was right. The trouble was caused not by the sensor but the power supplied to the sensor.

-9/24-

old condensers.jpg

I checked those three condensers. The top one in the photo(35V 100μF) was broken. It was the one used at right after rectifiers. I know such a condenser is under a high ripple charge.
Other two condensers were, amazingly, not broken. My tester showed their capacities were normal.
The pins of the top condenser are not showing for I cut them as I took it off in order not to hurt other devices on the board.
The pins were being soldered very close to the rectifires sharing the same lands. On top of it I couldn't use a heat clip.

-10/24-

Restoration (March 2018)
The pump which had been smoothly working stopped again soon in the new year. Though I tried a few possible improvements it didn't revive and I gave up repairing and posted about the affair to my blog and facebook on Feb.20.
However I couldn't stop thinking about reparing and I finally made up my mind to restore it though with no prospect of success.
The following is how I restored the pump.

-11/24-

fully restored.jpg

The photo was taken as I finally completed the restorarion.
I planned to use it not for daily life as before but only for watering flowers and washing cars. I installed a faucet newly for such purposes.
Thus the tank can be a reservoir of fresh water that can be used for drinking in case of emergency.
As I didn't own a thread cutter the piping was the game of combination of ready-made parts.

-12/24-

dead pump.jpg

The Pump Before Restoration:
The photo was taken soon after it stopped working.
While I was checking and working on the electronic controller for many weeks the motor stuck and the backward flow check valve, the old worn out rubber packing of which dried up, lost its function never to revive.
The motor had kept revolving with squeaking sound which I didn't notice then.

-13/24-

pump parts.jpg

Pump Parts:
From left to right, they are the casing(I partly broke it when detatchin), the impeller, the mechanical seal, o-rings, etc.
I bought new parts except the casing and the impeller.
Unfortunately I broke the casing as I struck it off the pump base.

-14/24-

bearing replacement.jpg

Replacing The Motor Bearings:
My bearing remover was too small for the motor and I had to lengthen the arms with pieces of wire. Luckily the bearing came off.
The bearing number was printed on the seal pasted on the motor. They were amazingly cheap.
A bearing can be warmed for easier work both in taking it off and in fittig it on.

-15/24-

plunger.jpg

Flow Sensor:
The inside and the plunger were thickly covered with rusy fur. (The plunger in the photo is cleaned.) This rusty fur once caused wrong response on the reed switch.
A whity cylindrical object is a plunger within it is molded a ring magnet.
When a faucet is opened it slides up pushed by water and makes the reed switch on. When a faucet is closed and water stops moving it slides down and the reed switch opens off.
In some internet articles the plunger is called a float. It isn't. The plunger is heavier than water and it never floats. I was troubled by the wrong name in understanding how it works.

-16/24-

pump casing.jpg

The photo, taken before it was cleaned, shows how I repaired the casing with a piece of stainless steel.
The casing which was unified to the motor had been stuck fast to the base. So I had to strike it hard many times to detach it out.
I tried to install a similar stainless piece using a bolt or a screw only in vain as the nuts collided.

-17/24-

photo interrupter.jpg

The red circled object in the photo is a photo interrupter installed in the fine sensor(water pressure sensor).
The device died a little while before I resolved on the restoration. The lost once made me give up repairing. The only information I could read out was it was manufactured by Sharp.

-18/24-

gp1a52hrj100f.jpg

I flatter myself that I didn't give up searching for an equivalent photo interrupter. The device must be less than 5mm in thickness and 12mmin width. I only knew them after I made mistakes two times. The first one I bought was 1mm too thick. The second one I bought was of a high intercepted output. The one I needed was of the low output.
I finally came to GP1A52HRJ00F by SHARP, which wasn't the type to be fitted by screws though. I glued it onto the board.

-19/24-

fine sensor circuit.jpg

Fine Sensor Circuit:
The circuit is connected parallel with the reed switch, which is operated by the magnet molded in the plunger.
The circuit and the behavior of the flow sensor show how the pump is automated.
The motor is started when the fine sensor is made on as any faucet is opened. The pump is kept working untill water stops flowing letting the plunger return to its resting position and the reed switch beeing left off.

-20/24-

pattern modification.jpg

Controller Board Modification:
Four red circles show the places where new lead wires are soldered. Two short red bars mark the places where the patterns are cut off. The area is shown enlarged at the right bottom corner.
Red circles from left to right are of:
DC-5V power, GND, water pressure sensor signal and for the motor operation signals to be input. The last one leads to the cathode of LED molded in the photo thyristor.

-21/24-

handmade controller.jpg

Handmade Substitute Controller
The controller consists of a sensor signal detector and an off-delay timer switch.
The sensor signals are detected high or low by one of pair comparator units in LM393. When the signal is detected high the comparator makes the original photo thyristor on.
The timer switch, built with a timer IC(555), gets started when the sensor signal is detected low triggered by the output of the other comparator unit. Its output prolong the motor operation for a few seconds.
I built each of them on a small sized print board that I pushed them into the original controller box.
The whole circuit design in pdf is here

-22/24-

Postscript
I had replaced the accumulator, which is an expendable article, twice before.
The pump had never got any electrical trouble before for nearly thirty years. It's a very tough apparatus. We are living now without children and the pressure applying pump is not actualy needed. But the water in the tank is always fresh as far as we use it. That is, it will be a very valuable water in case of a disaster.

-23/24-

Having Completed The Restoration
I wasn't confident of the restoration. It took many weeks but I enjoyed the restoration.
Before tackling the project I bought a junk pomp hoping to be able to repair it. But it was a real junk.
Unluckily I lost some money, which pushed me strong to restore my old pump too. I feel fulfillment now.
I tackled the work and consequently I could train myself how to use a circuit design software.
I could learn how to apply a comparator IC, too.
At first I started building the controller with transistors but my radio friend Mr.H advised me not to use them but to use a comparator IC. I had to learn how to use a comparator but now I thank him a lot for the usuful and profitable advice.

-24/24-

★Additional Repair 1★  as of 2021-09-23
repaired20210923.jpg  

Photo:re-repaired sensor

Our extra pump which we had used for giving water to the plants for three and a half years after the last restoration stopped working again. Luckily it revived again.
The trouble had been caused by the water that had leaked up into the pressure sensing unit through some invisible holes or clacks that had formed in the rubber diaphragm. (See the photo: the diaphragm is installed right below the coil spring). When water pressure is high it pushes up the lever which blocks the light for the photo-interruptor to work. It seemed to have been gradually damaged.
It is the one and only now. So I mended it with a sealing gel, the most low-priced one I found in Amazon. I applied it all over onto the diaphram on the water side. I could replace the damaged photo-interruptor with a new one I had luckily kept.
With these treatments the pump revived. It again responds, acuter now, to the lever operation of the watering nozzle. I hope the diaphrum lasts longer.

―Addition 1/1―

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★Additional Repair 2★   as of 2022-06-04
A trouble again! This time the motor didn't stop. The cause was a mal-connecton. The lead pointed by the red arrow in the photo was almost off the board. 1 resoldered

Photo:re-repaired sensor board

The soldering work took only a few minutes but I spent two full days to finish the whole repair work, checking the circuit and the control signals. Lucky was I being favored with the timing of finding the lead just as it came off the board.

―Addition 1/3―

 
2 diaghragm indide and outside

Photo:seal re-applied diaphragm

Making the use of this occasion I re-applied seal onto the diaphragm peeling off the old seal. Last time I was clumsy in applying seal. It became jagged and unfortunately water began to leak up later, very slightly though. This time I used a small soft painting brush soaking it with thinner as I had learned the seal dries and harden very quickly. I could paint it so that it formed a uniform thin film over the diaphragm. This time it's been successful in preventing the high pressured water from leaking up so far.

―Addition 2/3―

3 sensor lever

Photo: the lever with its action point heightened

Supposedly the diaphragm got old and hardened becoming less responsive to the changes of water presseur. As a measure I heightened the action point of the lever gluing a small piece of wooden chip as shown in the photo. It brought an immediate effect. The pump became responsive in starting and stopping to the on/off operation of the hose lever. The chip heightened the lever about 1.5mm saving the lever movement within about 1.5mm as I observed it.

―Addition 3/3―

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Solar Footlight

solar footlight whole.jpg

The photo is one of the three solar cell footlights we set up along the path to our house from the street. The approach is rather long and dark in the night.
The amount of light of each footlight is very small and can not light up the area around it. They only show which way is the path. However, they are better than nothing and we have been using them.
Well, one of them got out of order after using about two years. My wife asked me if I can repair it.
As I said, the light is not much useful and I was reluctant to repair it. However, I was interested in opening it and seeing how it was made.

-1/8-

solar footlight components.jpg

The light is composed of three parts. They can be assembled only by incerting and, with the head, turning a little clockwise until it clicks after incerting.
The solar cell is set on top of the head, inside of which are contained other electric parts being fixed on to the bottom cover. The cover is fastened to the head case by two small screws.
The LED illuminates downward at the center of the bottom cover, the light of which is reflected around by a cone shaped reflector.

-2/8-

solar footlight cell check.jpg

I tried to shoot the trouble as in the book, checking the voltage of the rechargeable battery first. It was the battery that looked very cheap, as if almost nothing else was cheaper. The voltage was 0.7mV. It's dead.
The solar cell worked. It responded to the light, OK.

-3/8-

solar footlight new cell.jpg

I tested the lamp with a new battery. The LED lit. So, I replaced the old battery with the new.
However, the repair was not complete. The light was unstable.

-4/8-

solar footlight switch.jpg

I suspected the mal function of the slide switch. I washed it with CAIG. But the light was still unstable.

-5/8-

solar footlight ic pin.jpg

Carefully watching, I found one of the IC pins, the far left pin out of the inline four at the lower end of the circuit board was not properly soldered. I resoldered it and the repairs were finished.

-6/8-

solar footlight mended.jpg

As in the photo, the lamp revived. The LED is switched off as the solar cell is exposed under certain amount of light.
On-off seemed to be controlled by the amount of light on the solar cell. A good mechanism!

-7/8-

Postscript
This time the repair was for the repair's sake.
My wife bought them for about 300yen each (amazingly cheap!). I bought two new rechargeable batteries for 598yen. They sell them two in one pakage. So I had to buy one of them for nothing.
Was it the repair for the sake of repair? No
I most enjoyed half the day repairing the lamp. It's a priceless way of spending time for me.

-8/8-

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Panasonic Washer Toilet Seat
DL-EXD10

dl-edx10.jpg

Photo:Model DL-EDX10, the same one as we have been using.
It was sold with a DIY kit (in 2012-3?). After using for a few years, the press switches have become less responsive gradually and one day, finally, they stopped working.

JUMP to the culprit and the measures taken.

The trouble was caused by water leaked into the arm where the controller board was fitted (beneath press buttons). All the tact switches on the board stopped functioning due to carbon, verdigris, etc that accumulated in and around them.
The followings are the process of repair. If you try yourself, it should be done at your own risk.

-1/15-

detaching screws m.jpg

Steps of dismantling the seat:
The followings are the steps. First, you'd better cover the floor with a bath towel or something alike to let it soak spilt water.
1. Stop water to the seat tank.
2. Take the hose off the seat assembly.
3. Empty the inner water tank.
4. Detach the seat forward(to your way) pushing the button at the right rear.
5. Unscrew 4 stainless screws.
Three of them are marked by red circles each and the rest by a green circle on the other side. 6. Prize the under plate, on which are mounted the main compornents, off the hooks from the upper cover.

-2/15-

inside machine m.jpg

You check the components mounted inside, such as the motor, plastic pipes, the nozzle and the power unit, etc if there were any unusual appearnces.
They all looked normal this time.

-3/15-

boardss.jpg

Repair of the controller:
The board is fitted inside the arm, screwed on to the upper cover.

-4/15-

board magnified.jpg

You screw off the controller boad carefully and turn it over, again carefully, in order to pull off two white connectors.
The connectors are showing themselves in the photo at the upper-left end of the board. After pulling them off, the boad is free to your hand.
At this stage I found verdigris here and there on the board.
Mending tact swithes:
I found all the 12 tact swithes, more or less, bore verdigris. The whole board itself was wet, too.
To begin with, I dried it and took off the switch for bottom washing and checked its conduction. The switch was dead.
I had no spare tact swithes then and so I opened it and cleaned the inside as I did with the Victor turntable, reassembled it and put it back to the board. The bottom washer function revived.
I ordered new tact swithes with which to replace the old ones later.
As the tact switches arrived later, I replaced the old ones with the new. The switches I ordered were 4-legged while the ones used on the board were 2-legged.
I converted 4-leg swithes into 2-legged. I had to contrive to fit them to the board, which I could manage to do successfully.

-5/15-

slit sealed.jpg

Giving waterproof:
The photo shows the bottom plate onto which the washer nozzle unit is mounted.
There were five possible places where water leaked in from. I took the following measures.
1. I blocked up two slits on both sides of the nozzle sylinder. They exist a little deep inside for which I cut out a proper shaped shield from a piece of plastic sheet and glued it.
2. The three oval cirlces indicate other possible slits, which I filled up with a water proof glue.
3. I re assembled the seat and it has been used with all the swithes functioning without troubles.
* (The measure was not appropriate. The seat again started to suffer mal function in about six months. See The second repair.
4. I installed DL-EG10, a later succeeding model of DL-EDX10, to the other toilet in our house, which I checked before installing if the same waterproof operation is necessary. The check was useless. DL-EG10 was a water-seepage-proof model. (Oct. 2015)

-6/15-

board2 m.jpg

Second Repair
To my disappointment, the seat began to suffer mal function in about six months and I had to repair it again.
The photo is showing the switches that bore verdigris again. Where had water leaked in?
I replaced all the tact switches except the one at the far end of the board(out of the photo). It looked quite healthy free from water.
This time, I drilled two new holes on the board for each tact switch to fit four-leg switchs tight.
I replaced one LED, too. One of the two pins was corroded.

-7/15-

inside covered m.jpg

Another water leak measure:
Water must have come from other than the slits mentioned above. My close inspection, however, couldn't shoot where did water come out.
The measure I took was to cover the tank unit (in the bigger red square) and the nozzle unit (in the smaller red square) independently with plastic bags to stop water from coming out.

-8/15-

board covered m.jpg

Then I covered the board likewise as shown in the photo.(March 2016)
I'm expecting the repair this time is successful.

-9/15-

The culprit and the measures taken.(The third repair)
On the occasion I replaced the gaskets of our two toilets, I happened to notice an irregular spill of water from the washer toilet seat other than that from a relief pipe. The spill turned out to be the real culprit that had been troubling us. It was coming out from the drain plug and socket made on the inner tank of the seat.
It was too unlikely the part for me to notice much earlier. I took the following measures.

-10/15-

sealed drain hole.jpg

I filled all the apertures around the drain faucet with sealant.
With the advantage of hindsight though, the faucet is located closer to the controller board and if any water splashed upward at the faucet it easily spreads inside the apparatus container some reaching the board.
It seems that the leak was caused by the poor quality of the faucet. I replaced the old O-ring with the new but the leak didn't stop. Incidentally, the size of the ring was the same with "SANEI 10."

-11/15-

sealed drain hole inside.jpg

Top view of the aperture inside the apparatus container.
The drain faucet is installed on the tank facing downward. I applied sealant there, too.
Water must have been splashing up into the apparatus container from this aperture.

-12/15-

seal taped drain plug.jpg

This is the plug used for the drain faucet. To help make leak lesser, I applied seal tape.
I split a piece of seal tape and made it slender in order to fit it to the plug. The white thing beyond the plug is a remaining piece.
I applied it thicker but couldn't stop the leak completely. However, as the sealant stops water now from getting into the container, I decided to let drops of leak go on, for it occurs only as you use washing.

-13/15-

Postscript
This is the plug used for the drain faucet. To help make leak lesser, I applied seal tape.
I split a piece of seal tape and made it slender in order to fit it to the plug. The white thing beyond the plug is a remaining piece.
I applied it thicker but couldn't stop the leak completely. However, as the sealant stops water now from getting into the container, I decided to let drops of leak go on, for it occurs only as you use washing.

I suspect the seat had a defect in design or with materials, for a measure was being taken with the later model.
Apart from the troubles, I was impressed by the sturdiness of the IC chip. When the controller board was wet, the chip was wet too and suffered burden more than designed as the switches were broken. But the chip endured it. Thanks to the tough cip, the seat revived by replacing the switches again.(March 2016)

-14/15-

Postscript -2- Replacement
About a month ago the seat made a big gear noise and the nozzle stopped moving. I tried pressing switches and moving the nozzle by hand, and finally found the seat can be used if you move the nozzle by hand. I am the only user of the seat and I accepted the trouble and kept on using the seat manually.
However, a shop made a discount sale recently for the card customers and we found a successional washer seat(DL-EJX10) was among the list. It turned out that with saved points we can get one very reasonably. So we bought a new one and replaced with the old one which I loved so long.
Hereafter there will be no more additional writing about the seat. Thank you very much for finding and reading this page.(July 20, 2017)

-15/15-

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fl lamp s.jpg
Fluorescent Lighting Equipment

Preface
One of the fluorescent lamps (hereafter cited as fl-lamp) in my study stopped responding the switch one day. It took some time to shoot the trouble but I found it was caused by detachment of soldered wires. It occured at one of the sockets to which one end of an fl-lamp is inserted. I have experienced dead lamps and glow swiches many times but never such a trouble.
As usual with me, I tried to repair it. The repair was successfully finished saving a purchase of a new lighting equipment. Here are the process of the repair for your information.

-1/17-

fl lamp.jpg

This equipment died.
I wanted to repair it there on the ceiling but it seemed impossiboe. So I detached it down.
The photo was taken after the repair.

-2/17-

button.jpg

Important! You first put off the wall switch for the lamp.
Before taking off the equipment from the ceiling, you take off the cover by pushing the buttons shown in the green circle. There are two buttons, one on each side. There are cases you need more force than you expect. Some might have experienced it.

-3/17-

naked.jpg

The photo shows the naked equipment after the cover and fl-lamps are taken off. It is fixed onto the ceiling with four screws shown in the smaller circles.
The screw in the green cirle functions different than other three. You don't take it off. The explanation is given later.
Before taking off the screws you have to take off the power wires off the socket that is in the bigger dark blue circle.
Once again, when doing this by yourself, never forget to put off the wall switch or the corresponding circuit braker!

-4/17-

cords on.jpg

A close-up photo of the power line connector.
The power is led to the equipment from behind the ceiling out of the hole in the center. The connected wires are retained by the spring force.

-5/17-

cords off.jpg

Pressing the square button in the green circle enables you to pull off the wires from the connector. I used a minus driver to press it. The pulling off was smooth.
You don't have to push the button when inserting wires because the connector has one-way cruches inside.
This is the last process before taking off the equipment.

-6/17-

last screw.jpg

Now the process of taking off the three screws.
As was mentioned above, the screw in the green circle is not taken off.
Explanation of the screw: It is used to temporarily hold the naked equipment on to the ceiling. It must be driven before enything else and not be tightened all the way to the end so that you can hook the equipment to the screw head by sliding it a little. Thus you can use your both hands for driving other three screws.
The process this time is taking off, not fitting it on. So, you take off other three screws first, then loosen the last one only a little in order to slide the whole equipment to the downward way in the case shown in the photo.

-7/17-

socket off.jpg

The processed hereafter are done on a bench.
Raise one of the holding nails and you can take off the socket free.
The photo shows how wonderfully? the soldered wires came off the brush.

-8/17-

solder came off.jpg

The photo is a close-up of the detached wires. I suspect the cleaning of the brush surface was insufficient when they were soldered.

-9/17-

composit parts.jpg

The photo shows the parts that compose the socket. Brushes are polished.
Before polishing, the soldered spots were black.

-10/17-

.jpg

Close-up of the brushes.

-11/17-

resoldered.jpg

One of the brushes onto which a wire was resoldered.
They must be soldered so that they can be fit in the socket as showen in the next photo

-12/17-

reassembling1.jpg

The brushes are set inside the outer frame of the socket.

-13/17-

reassembling2.jpg

The inner retainer is set.

-14/17-

reassembling3.jpg

The thin pastic outer retainer is set with an eyelet rivet.

-15/17-

reassembling done.jpg

To complete the repair you go backward the processes of disassembling. Place back the socket, bend back the nail to hold the socket and you finish what you have to do on the bench.
Now, you hook it on to the ceiling and drive screws to tightly fit the equipment to the ceiling, incert the power wires to the connector, place back fl-lamps and the cover.
The photo at the top of this page was taken at this stage.

-16/17-

Postscript
The production of incandescent light bulbs has been stopped in Japan, and it has been reported that the fate of fl-lamps is going to be the same very soon. In electric stores the LED lamps in the shapes and sizes of fl-lamps are sold with the notes that they last twice as long and their running cost is less than one third as the fl-lamps.
However, the price is several to fifteen times higher than that of fl-lamps. That is, with such a price the replacing of fl-lamps with LED lamps in our house will not be economical while we can buy the former.

-17/17-

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Gas/Solar Heated Water Selector Valves

e valve.jpg

Photo: Gas/Solar Heated Water Selector Valves.
There are two water heating systems installed in our house, a solar heater and a gas heater. Solar heated water is stored in a tank on sunny days but it doesn't work on cloudy or rainy days. On such days or when we have used up the stored heated water, we switch the valves for a gas water heater. The witches are electric motor driven.

The original valve switches were solenoid valves but they stopped working one day.
The trouble was caused by a check valve which was badly worn out, not the solenoid valves. However, the solenoid valves were old and I repladed them with the new motor driven valves.

-1/4-

check valve.jpg

The illustration shows a section of the check valve.(Thanks to Kitz)
The trouble was that the valve was out of its guide and choking water.
As usual with me, I made temporary repairs to the valve by making the shaft longer by about 3mm so that the valve doesn't get out of the guide.

The material I used was a piece of brass pipe I happened to have then. The diameter was luckily the same with the shaft. I ground the shaft and capped it with the brass piece and soldered them. The check valve revived!
Later, I replaced the valves but I made the shaft of the new valve longer before installing.

-2/4-

change switch.jpg

The photo shows the switch panel.
The upper switch, the original one, is for power and the lower for valve control.
The solenoid valves were on-off controled devices but the motor controled ones needed forward/backward rotation control. I used a 6-pole/2-way toggle switch picked up from among . my stock switches.

-3/4-

Postscript
When the mal function happened, I called a contractor and asked him to repair it. Somehow, he didn't accept it. Instead, he recommended me to replace the whole system. So, I made up my mind to repair it myself.

-4/4-

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Futon Dryer Timer Switch


(Installed on 2019/12/30)

.jpg
I wanted to replace our old futon dryer with the one in the photo but I found the timer switch didn't work. It's newer but it had been left unused many years. You could use it with a timer controlled extended outlet but as usual, I tried fixing it.

―1/7―

.jpg
I could open it by only two steps.
1.You pull off the timer nob and take off two screws which fix the timer inside.
2.You take off the filter cover and the filter and then take off five screws at the places marked with green circles.
It should be opened with its backside up.

―2/7―

.jpg
The photo shows the inside. The black square thing is the timer switch loosely kept in its place.

―3/7―

.jpg
The photo shows the timer switch completely taken off the dryer. The circuit tester showed the motor coil, luckily, wasn't broken. Why then the motor doesn't revolve?

―4/7―

.jpg
The photo shows the inside of the motor. It was held tight on the timer body with kind of one-way rachets. And so was its cover.

―5/7―

.jpg
I pulled off the rotor. The coil is installed inside the white outer plastic mold. I felt some resistance as I pulled it out. The rotor seemed to have been stuck on to the bottom with hardened grease. The motor, after I wetted the shaft and the rotor seat with machine oil, revived!

―6/7―

.jpg

Incidentally, I checked the gear but I made a mistake as I opened it. I should have been more careful.
I opened it without checking which side should be up or down and small cogwheels came off their places. It took me some time to set them back as shown in the photo.
The nob and the places of two cogwheels for selecting power frequencies were being made to be correctly placed back.The timer switch revived. Banzai!

―7/7―
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Fixing An Old Favorit Mouse


(Installed on 2020/)

.jpg
The right button of this mouse stopped working. I bought it around the beginning of the century when optical mice began replacing mechanical ball mice. I have long used it and it fitted with my palm now. So, I tried to fix it.
I surmised a microswitch under the right button was out of order.

―1/3―

2 worn out pit.jpg
My circuit tester however showed the on-off function of the microswitch was normal. The trouble turned out to be much simple. It was caused by the abrasion of the mouse button. The tiny pit in the red circle in the photo above is it.

―2/3―

3 small plastic pieces glued .jpg

There are three microswitches in the mouse, among which the one on this side is in charge of the right button. The point is the stroke of the white contact button. It's only about 1/2mm and the value is almost equal to the depth of the worn out pit. So, to let the white contact buttons pressed securely I glued a small pieces of hard plastic sheet onto the switches as shown in the photo.
In finishing the treatment I cleaned the inside and reassembled it. The treatment was perfect. The mouse revived with smooth operation.

―3/3―
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Fixing Yanton T-466 Transceiver


(Installed on 2021/04/01)

1-yanton t-466 before.jpg
A friend of mine gave me a Yanton T-466, a UHF transceiver for radio amateurs. It had been left unused for years and had malfunctions with the display and the keys. I surmised they were caused by the bad contacts, not by the broken electric circuits nor the parts.

―1/7―

2-back cover removed.jpg
Removing the back lid, on which is fixed a battery, revealed the insulator on the other side of which is installed a circuit board. The insulator is fixed onto the front cover with two screws at the bottom. But one of them was behind an inspection seal as shown in the photo inside an yellow circle. So, you had to notice the idea first before taking the insulator off the outer plastic case.

―2/7―

3-inner module detached.jpg
The circuit board was fixed on to the insulator with several screws. The photo is important for installing the board back to the insulator.

―3/7―

4-print board detached.jpg
First by making the two red wires free from the speaker and then loosening the screws you can separate the circuit board from the insulator.

―4/7―

5-contact points cleaned.jpg
By removing the chrome frame and the display panel you can access a line of contact lands from which the display get signals. The frame, which was hooked with nails, was easily taken off the circuit board.
I cleaned the lands and the key pad sensors with CAIG and alcohol and finished the work by jetting air duster against them.

―5/7―

6-yanton t-466 after.jpg

Yanton T466 revived showing proper numbers on the display as keys are pressed. That is I set 82.5 on the display, which is the frequency(MHz) of NHK-FM station in Nagoya, and I could hear the broadcast!

―6/7―

7-power meter.jpg
Although the temporary poor connection of the power/swr meter and a dummy registor resulted full scale swr as shown in the photo, it showed the T-466 could transmit.
It revived okay but if you don't use it often the contact points and sensors would become dull again. I have no plan to use it. How could I keep it always ready to be used?

―7/7―
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Panasonic KX-PW22CLH
Fixing A Liquid Crystal Display

(Installed on 2021/04/11)

1-panasonic fax.jpg
It had been some time since our fax machine lost its display function. It had functioned normal other than the display and we had accepted the trouble not sustaining a large outlay. However we used it like using a keyboard without being able to see what was inputted. So I decided to try fixing it not with a prospect of success though. Luckily, the display function came back as you see in the photo.

―1/8―

2-fax display before fixed.jpg
The photo shows the display before it was fixed. Only backlight was alive.

―2/8―

3-input-output panel open.jpg
The photo shows the machine beeing opened for changing rolls of paper. The dial and other buttons, the display and the receiver holder were being installed inside this cover lid. I searched for the possible screws in order to take off the lid. I couldn't find any or, to begin with, the hinges were at the invisible places even with a light. I spent the first day only gazing and peeping.

―3/8―

4-hinges.jpg
I searched over the internet and found a description. It was about a different type of fax machine but the writer opened it with 'force'. It gave me a hint. I was determind.
On the following day, I inserted a minus driver into a gap at the place shown by a yellow circle and levered the hinge outward. The hinge came off upword with a popping sound!

―4/8―

5-print board appeared.jpg
The lid finally came off with two set of cables being connected to the body. Luckily they were narrowly long enough for me to access the display unit on the print board. However, the work of taking off the unit was very hard.

―5/8―

6-taking off display unit.jpg
The unit was easily taken off the board as it was fixed with plastic claws. The numbers like 98.09.04 were printed on the print board. It seemed to be the date of procuction of the unit telling it might have been 23 years old.

―6/8―

7-ribon feeder to be cleaned.jpg
Finally the unit came off as shown in the photo. The pair of a red and a black cables were power feeders to backlight LEDs. With regard to the ribbon feeder or the matrix signal feeder to the display, one end looked firmly set to the display. So I decided not to touch it. I suspected the other end which came off from the connector on the board. I cleaned them both with CAIG, applying duster spray against them in finishing the work.

―7/8―

8-display revived.jpg
After a long, hard and cautious reassembling work I put on the switch, with an uneasy feeling. The display came back! The whole work took me three days but I was finally rewarded with very clear letters which were even soothing, too.

―8/8―
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Fixing A Dehumidifier.


(Installed on 2021/05/27)
Additional Fixing of Ribbon Cable here

1-after repair f-view.jpg
On May 16 the Meteorological Agency announced the start of the rainy season for our region. Unusually early! We pulled out our old defumidifier and put it on. But it didn't start. I checked it and knew the power wasn't sent to the compressor. Connectors were all fine. I connected AC100V direct to the compressor. It workded! So I took off the circuit board and checked the power circuit which was connected to the compressor.

―1/5―

2-bad diodes.jpg
The making and breaking the circuit to the compressor was controlled with a relay. I found it wasn't working because the diode (in the white circle in the photo) which was to short-circuit the counter electromotive force that arises in the relay coil when its power is shut off was disturbing in someway. Its leads were badly rusted and the rust had gone inside the diode.

―2/5―

3-new diodes installed.jpg
Luckily I owned diodes and replaced it with a new one. Taking this opportunity I replaced one other diode in the yellow circle too.
The place where the dehumidifier had been kept seemed bad and many other leads were rusted too. I rub the rust off them as much as possible and coated them with lacquer hoping them beeing kept from rusting.

―3/5―

4-diodes taken out.jpg
The pnoto shows the poor diodes taken off the board. The one on the right was used for the compressor relay. It crumbled to the touch. How come the leads were made of iron wire, instead of copper or brass?

―4/5―

5-con-panel after repair.jpg
The dehumidifier revived. The indicators and the functions responded to the button switches. The fixing was rather easy and smooth as the circuit board was easily detached.

―3/5―
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Additional Fixing Of The Ribbon Cable
(Installed on 2023/02/07)

ribbon cable.jpg
I switched it on after a long interval. It didn't respond. After putting it on and off repeatedly the fan started to move but not the compressor. Opening it I immediately knew the ribbon cable is the cause. I experienced such troubles with the fax machine and the washer toilet seat.
Corrosion looked to be developing on the contacts as shown in the red circle. I rubbed them clean applying deoxidizer and the dehumidifier revived.

―additional 1/2―

indicator panel.jpg
The photo shows the control panel that revived. None of other electrical part was wrong.

―additional 2/2―
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Repairing A Shaver


(Installed on 2021/07/02)

1-shaver whole view.jpg
I did the second operation on my very old favorite shaver. The spinning had started to be irregular.
2-inside.jpg
The photo shows the inside its back lid being taken off. You can take out the motor by welding off the connecting leads.

―2/7―

3-motor rotor.jpg
The photo shows the rotor with two grooves made by the original brushes. It can be used okay.

―3/7―

4-a worn brush.jpg
The two revamped brushes which had been installed since the first operation. One was worn down uneven.

―4/7―

5-making a brush.jpg
I revamped the bad one again using the thin base metal for connector pins.

―5/7―

6-renovated brushes.jpg
I curved the tips of the brushes so that they can contact the rotor tighter.

―6/7―

7-new brushes.jpg
The newly devised brushed were installed as shown in the photo. The shaver revived. The Ni-MH rechargeable battery, which is out of date now, still works well. Full charged it gives me ten-time(morning) shavings, though it originally gave me 14-morning shavings. How long more can it be used?

―7/7―
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Repairing Electric Hair Clippers


(Installed on 2021/07/17)

1-clippers fixing done.jpg
I had to repair the electrical hair clippers I bought long long time ago. I broke them due to my too hasty interpretaion. That is, I remembered we had electric hair clippers when I asked my wife to cut my hair the other day. I was in a hurry.
The photo above shows the clippers I repaired.

―1/7―

2-charging-ac.jpg
The description I misinterpreted was 'charging・AC'(充電・交流) which was printed on the clippers. I didn't remember well how I used them. I read 'recharge with AC 100V.' They clacked and died on connecting them to AC 100V. It turned out they were desighed to work on DC 3.2 volts. I had only lost the power adapter.

―2/7―

3-polot lamp parts.jpg
It revived by replacing three broken parts with new ones. First I replaced a pilot led lamp and a resistor as shown in the photo. Those in the red circle are the broken ones. Amazingly I found an almost identical led in my junk box.

―3/7―

4-replacing resistors.jpg
Next, I replaced a resistor on the switch board. The broken one in the red circle was replaced by two resistors in the green circle, one of which I covered with a piece of black tube. I needed two resistors to make the same value. The diode next to the resistors wasn't broken, the function of which was unknown. I didn't toutch it.

―4/7―

5-deform the section shape.jpg
Encasing back the motor and the battery unit into the outer case for water proof was a hard job. The height of the cross section of the unit at the switch lever position was higher than that of the outer case. I didn't realize it when I forcibly took it out. I ran aground!
Luckily I hit upon the idea the following day to deform the shape of the cross section of the outer case with a vise. It worked. The photo shows a process.

―5/7―

6-insertion done.jpg
The lower half of the photo shows the inner unit is being inserted to the right position. The switch lever notch is just at the operation hole.
The upper half of the photo shows the outer switch lever is being set to the notch over which the grip cover is to be set. The repair is almost done.

―6/7―

7-boxing to keep.jpg
Finishing the repair I placed the clippers with all the needed accessaries in one new cardboard box.
The power adapter, which can supply DC3V, had been used for a kerosene pump. The adaper is essential as the built-in rechargeable batteries were almost dead.

―7/7―
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Repairing A Circulator


(Installed on 2021/08/07)

1-circulator front.jpg
An old circulator stopped working. The cause was it exhausted the lubricating oil. Some of the motors of this kind, after using for a long period, running out of lubricating oil, their bearings worn off the axles get loose and many of them start to rattle or screech, while others the axles and the bearings get stuck to each other. The motor of this circulator belonged to the latter.

―1/6―

2-circulator back cover off.jpg
Access to the motor was easy. The rear cover came off by turning off four screws and the fan, which was also covering the motor, came off by turning a nut.

―2/6―

3-circulator motor appeared.jpg
The motor was easily mounted off by turning off four screws.

―3/6―

4-circulator oil pockets.jpg
The motor itself was also easily took apart. After blowing off dust and cleaning I let lublication oil infiltrate into the felt-like oil keeper of the bearings.

―4/6―

5-cirlulator motor coil.jpg
This photo is nothing to do with the repair. The beautifully wound coil intrigued me to keep it here.

―5/6―

6-circulator with oil cans.jpg
Before finishing the repair by putting back the cover I took this as a commemorative photo. The circulator revived and has been working vigorously.

―6/6―
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PC MONITOR


(Installed on 2021/11/29)

1RDT1713S.jpg
One of our old pc monitors died the other day. It had been used as an additional monitor for the tablet pc dedicated to playing music files. Putting on the switch that day a blue line flashed on the display and nothing else happened. My experience told me a condenser or a bridge rectifier in the power circuit died.

―1/7―

2taking off stand.jpg
I decided to try to repair it wanting to use it as a monitor for a raspberry pi. First you had to take off the stand in order to access to the circuit board. The stand was fixed on to the monitor with two screws. Taking off the make-up cover the screws could be loosened through the driver holes.

―2/7―

3taking off rear cover.jpg
Taking off the stand you could take off the plastic rear cover fit on to the frame with small latchet claws after taking off four bolts that fasten the cover onto D-sub-15-pin and RGB conectors. The connectors are fixed to the body inside. Then the cover could be taken off by prying it off carefully with a small minus driver.

―3/7―

4taking off circuit board cover.jpg
Taking off the plastic rear cover, the metal cover of the circuit board appears. It was neatly fixed onto the main metal board. It could be taken off sliding downward after taking off one fixing screw.

―4/7―

5pointed dead condenser.jpg
The condenser pointed with the red arrow is the dead one. The (black four legged) bridge rectifier right side below wasn't broken. I usually diagnose if they are okay or not according to the values I get with a circuit tester. It needs experience as they are on the circut and connected to other parts.

―5/7―

6new condenser.jpg
I installed new condensers as shown in the photo. They are parallelly connected two 450V/47μF condensers. Living in a remote corner of the country I couldn't get an identical one.

―6/7―

7monitor revived.jpg
The monitor revived!

―7/7―
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VACUUM CLEANER
TOSHIBA VC-TRE2(BK)

☆First Article☆ (Installed on 2022/01/31)
● The third repaire of the cleaner.(2022/05/11)here
● The second repaire of the cleaner.(2022/03/25)here

1 vc-tre2(kb).jpg
Our vaccum cleaner for downstair rooms stopped moving. We had used it for not so many years. I had experienced replacing brushes of old cleaners. So I opened it to see if I could repair it likewise.

―1/10―

2 taking off cover.jpg
The outer cover over the motor and the circuit board was fixed with three screws, two from the upper side and one from the bottom. I used the flexible driver after very long years.

―2/10―

3 inside.jpg
The circuit board was covered with a piece of glass cloth and fixed over the motor with two hooks.

―3/10―

4 motor cover.jpg
On to the circuit board were wired a pair of control lines and three power lines in different colors.
The blue line was wired to one of the brushes as well as to the thermo-fuse, the other end of which was wired to one of the AC inlets. The fuse was fixed at the place where it could stick fast to the motor.
The red line was wired to the other AC inlet.
The white line, which was the output line of the circuit, was wired to the other brush.

―4/10―

5 rear panel.jpg
The motor cover could be taken off after the rear panel, which had many holes in order to let out blowing air from the turbo fan, was taken off sliding upward.

―5/10―

6 motor cover hooks.jpg
The motor fixing cover was fixed with two hooks. The one in the red circle is the one on the right side.

―6/10―

7 brush.jpg
Taking off the cover you could see how the motor was installed. One of the brushes was easily checked. Both brushes were not badly worn. Connecting directly to AC 100V, the motor powerfully rotated showing the thermo fuse was not broken. The control buttons(switches) were normal too.  

―7/10―

8 broken triac.jpg
The trouble was invisible but was surely on the circuit board. So I relied this time on the probability that electric devices under the heavier load likely to get their life span shortened more than those under the lighter load, which I learned through my experiences.
I decided to try replacing the triac with a new one, the letters on which read "TOYOBO TB16A6YE". I ordered a piece of BTA24-600CW from Akizuki Denshi Tsusho Co., Ltd. as it satisfied the following spec of TB16A6Y as VDRM=600V, IT(RMS)=16A and ITSM=160/146 costing me less than ¥1000 including postage.

―8/10―

9 triac replaced.jpg
A few days later the triac arrived with the note from Akizuki. The note included a kind of written apology for the delaying delivery due to a shortage of workers under the pandemic of covid 19.
Replacing triacs took more time than I estimated. The heat capacity of the lug terminals that held faston male terminals tight on to the board dissipated much heat from my soldering iron that old solder remained in the terminal holes. I had to re-drill the holes and then I could solder the new one tight and beautiful. The triac in the red circle in the photo is the one taken off with its lead pins cut.
How would be the result?

―9/10―

10 repair succeeded.jpg
The result was BINGO! My speculation hit the trouble this time. The vaccum cleaner revived! The photo shows the blowing exhaust? I tried to show it with a piece of paper as I wanted to share my delight with you. We can possibly use the cleaner many more years.

―10/10―

☆Another Repair☆ 2nd repair done.jpg
The cleaner presently stopped again. Luckily, it revived after replacing a photo-coupler with a new one with similar specifications. The device is pointed with a yellow arrow in the photo. At first from the probing result with a circuit tester suggested me the bidirectional zener diode, which is pointed with a green arrow in the photo was broken. It wasn't.
The cleaner revived but the control buttons lost their original functions, perhaps because the specifications of the new coupler are not quite the same with the original one. I tried to mend the functions by exchanging the zener diodes. It didn't work. However, I can use the cleaner with the medium power anyway with which I mostly use it.

―addition 1/1―

☆Third Repair☆   (Installed on 2022/05/10)
Top of this article. here tlp old and new_s.jpg
Using the cleaner after the second repair I learned that a vacuum cleaner that is deprived of the soft(weak) mode is very uncomfortable to use. So I searched for the photo-coupler TLP421 originally used in the TOSHIBA VC-TRE2. Luckily I found they were still sold at Wakamatsu Tsusho. I purchased one and replaced with it the improper one I installed a few months ago.
The photo shows the new TLP421 I newly bought and the original broken one in the green circle.

―addition 1/2―


tlp421 installed.jpg
The letters printed on the device are different except for 'P421'. It made me feel slightly uneasy. However, the coupler worked alright. The cleaner revived with the perfect control of vacuum strength. Above all, it resumed original soft start.
The soft start is a function of human engineering. It's different from a noisy and shaking start that irritates us.

―addition 2/2―
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Panasonic DC Fan
F-CL339


(Installed on 2022/07/07)

1panasonic f-cl338.jpg
I was asked to repair a Panasonic F-CL33. It worked but very unstably. The symptoms appeared irregularly when you let it swing.

―1/10―

2upper wiring.jpg
The fan is equipped with a dedicated small motor for swinging, on top of which was mounted a black plastic box for the motor control circuit.
First I surmised the trouble was related with the control circuit of the swinging motor. Was there a hall device in the box? There wasn't. The circuit seemed quite healthy too.
Next I touched and moved the wires. The trouble appeared irregularly. The wires were all well-connected with the closed-end connectors. The trouble lurked inside the cables. One wire in dark blue out of five was very unhealthy. Bypassing the wire almost killed the trouble but not perfectly. There were two more unhealty wires. Breaking down of covered wires was most unlikely to my standard.

―2/10―

3corroded wires.jpg
I spotted three unhealthy portions on three cables. The trouble was identified. There was corrosion inside vinyl tubes. Some wires were very slender and others broken.

―3/10―

4washing.jpg
Unfortunately the cab tire cable turned out to be a kind of dedicated one to the fan. So I bought a piece of similar cable at a net shop planning to modify it to fit to the fan. While waiting for the cable to be delivered I cleaned and checked the fan for the cable replacement. (Photo above: Bottom plate being washed.)

―4/10―

5drying.jpg
I washed clean all the washable parts.

―5/10―

6bottom cap.jpg
The cable had to be put through a tight hole inside the stand of the fan. In order to do the work you needed to take off the bottom cap ignoring the description(ネジ分解禁止) that forbade doing so.

―6/10―

7pulling out old cables.jpg
Over the outer cover of the old cable had been applied grease in order to make it slippery, which I didn't for the new one.

―7/10―

8new cabtire cable.jpg
The new cable I got was thicker and harder that I partially peeled off the outer cover in order to make the portion slender. To my regret it turned out that the portion wasn't long enough.

―8/10―

9lengthening cables.jpg
In order to save the trouble of taking off and installing the cable again I made it longer by adding a short piece of wire onto the top end of each wire.

―9/10―

10new wiring done.jpg
By replacing the cab tire cable the fan perfectly revived. It took three days.
The fan revived okay but the wire corrosion inside the cable was most unlikely. I had experienced a similar poor quality control with a Panasonic washer toilet seat. A big pep to Panasonic!

―10/10―
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Panasonic Washing Machine
NA-FA90H5


(Installed on 2022/10/22)

1_NA-FA90H5.jpg
It started some six months ago. Our washing machine had begun to go on strike (for safety's sake?) repeating locking sound three times each time we wanted it. We had tenaciously repeated switching it on until it worked but finally it refused to work the other day. The 'lid locked' sign disappeared and never came back. I replaced the broken lock unit with the new one and it revived.

―1/8―

2_control unit.jpg
The photo shows the back side of the upper block inside of which the control unit is installed. It was fixed to the body only with four screws.

―2/8―

3_lock plunger.jpg
Taking off the black inner panel you could access the lock unit. It's pointed by the red arrow. The 'lid locked' signal leads were connected to the lid detector in series.

―3/8―

4_new locker_switch.jpg
I checked the resistance of the lock signal switch built in the new lock unit. The value was 'o' whereas the value of the broken one was about 500Ω.

―4/8―

5_lock sign.jpg
With the new lock unit installed I could start the machine normally. It started to work with only one 'lock' sound as well as with the 'lid locked(=ふたロック)' indication. Repair finished!

―5/8―

6_lock signal switch.jpg
Hereafter is the report of my inquiry of the cause of the trouble.
The photo shows the inside of the lock unit. In the yellow oval is the built-in contact switch by way of which the safety signal of 'lid locked' is sent to the control console. The circuit tester shows its 'ON' resistance is about 500Ω. The value was naught with the new lock unit. Until I checked it, I thought the switch originally could be resistant. It wasn't.

―6/8―

7_signal contact switch inside.jpg
I opened the contact switch as shown in the photo. The tiny case of the switch was doubly sealed with thin vinyl-like film and thicker rubber-like stuff. However, the trouble was caused by the thin insulating stuff which had formed over the contact surface of the disk spring. The other side was
The disk spring mechanism:
The disk spring with its circular edge electrically connects the electrodes when pushed changing its 凸 profile into 凹 profile. When the push is released the disk springs back to its original frofile breaking the connection beween the electrodes.

―7/8―

8_disk spring.jpg
The 凹 side of the disk spring seemed to be corroded. My circuit tester, as shown in the photo, couldn't detect conduction. The surface seemed to be sulfurized. The other side, which was plated it seemed with chrome, was still conductive. The small hole at the center seemed to be made by frictional wear.
The housing of the switch was doubly sealed with some chemical stuff but it couldn't stop sulfuration? Usually the electrodes and disk edge rub and polish each other and the conduction is maintained long. Did we have used the washing machine too long? Or was the use of optical sensor too costly?

8/8
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Hitachi Cleaner CV-WD5
Replacing Carbon Brushes


(Installed on 2022/12/31)

1hitachi cleaner cv-wd5.jpg
It's the twenty year-old cleaner dedicated to the upper floor, which suddenly died the other day while using. I could judge the carbon brush was damaged by the smell. One of the carbon brushes was replaced new years ago I remember.

―1/9―

2three screws to open.jpg
The upper cover could be taken off by screwing off only three screws which are marked with red circles.

―2/9―

3cleaner opened.jpg
The photo shows the inside the body where the motor, swathed with cushioning material, was placed fit tightly in the plastic cradle under the control board which, also forming an upper part of the cradle, kept the motor at the place under the upper cover.
The circled part in the photo shows the naked motor. The brush unit was plugged in at the place marked with red circle and was fixed with one screw. The same was true with the other unit on the opposite side.

―3/9―

 
4worn away brushes.jpg
This is a brush unit and the other worn out carbon brush.

―4/9―

5brush structure.jpg
The photo shows the original brush taken out from the unit body. It had not been replaced before and it's time to be replaced together with the other one.

―5/9―

6makita brushes.jpg
I bought Makita's CB-124 at a nearby DIY shop. They were 0.5mm too big both in width and thickness. I grinded them into the the proper size.

―6/9―

7new leads.jpg
I lengthened the leads using solder soaking mesh wire and made holes at their ends in order to fix them to the electrodes where they were welded riginally (see 5/9 above). My best device in this work.  

―7/9―

8new brushes.jpg
The new brushes were made as shown above. I replaced the weakened spring with makita's springs doubled. Luckily they made a proper spring.

―8/9―

9commutator.jpg
I checked the commutator, which was considerably worn off. The cleaner might stop next time caused either by the brush or the commutator. In any case there might not be the third replacement of the brush.
Most importantly the cleaner revived. It will work for some more years I hope.

―9/9―
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Repairing A Honda Little Cub
&
Making It Batteryless


(Installed on 2023/04/26)

The 20-year old motorbike I rode the other day after many many months had lost its healthy performance. The engine stopped many times plus it didn't respond the accelerator smoothly. Even after the engine got warmed the idling didn't continue long.1_new cdi unit.jpg
I replaced the old CDI unit with a new one. It is pointed with the red arrow in the photo where the old unit is on the swing arm. The bike revived.

―1/2―

2_condenser.jpg
The battery, to which I hadn't pay attention for many years, had been completely dead. I took it off and installed a chemical condenser instead as shown in the photo.
With the engine revolving at about 1000rpm or over the horn and the winkers got back their normal functions saving me from raising my arm when turning. The headlight became brighter too.
I'm worried a little about a harmful influence on the regulator and the generator. However getting into action has the highest priority at my age.

―2/2―
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