Korg 01/W „no sound“ repair

A few weeks ago my 01/W started sounding „hissy“ and distorted and the output level dropped audibly. After a short power off it recovered without further action. But then, on the next day, all analog outputs were dead.

When I opened the housing I found two leaked electrolytic capacitors on the mainboard’s sub-PSU for the DAC and analog stages. This ±5 volts sub-PSU with two 100 mA voltage regulators is disposed behind the ±12 volts stabilisation circuitry of the main PSU and supplies stable and noise-free local voltages.

The caps C95 and C96 had ruptured and the sub-PSU and even more distant parts were spattered with electrolyt. And the really bad thing about leaked electrolyt on a printed circuit board is that it causes corrosion and damage of metallic parts and circuit traces. See the „overgrown“ capacitor C100 or the diode D3 on the photos for an impression of how this affects and proceeds.

To clean this type of mess I prefer cotton swabs heavily soaked with isopropanol (isopropyl alcohol). There’s no need to spare with the isopropanol, it does not do any harm to electronic components and evaporates without residue. And the cleaning should be repeated a few times with fresh swabs.

What has been left over from the „acid attack“ on my 01/W did not look dramatic at first. I replaced the two evil caps, connected the mainboard and powered up the 01/W, but there was no sound. While measuring I found that the negative leg around the IC52 (79L05) was operational but IC53 (78L05) floated around at 0 volts on it’s output and input. Then I noticed that one of the C100 capacitor’s leads had been „eaten“ by the acid and — more important — the +12 volt trace below the lead had also been etched away.

So I replaced C100 and patched the broken trace by scraping off a bit of solder resist and bridging it with solder. As you can see on the photos I also replaced IC53, which stabilised at 4.5 volts and not 5.0 volts. Of course, it is not state of the art to replace an SOT89 SMD component with a TO92 through-hole component, but firstly it would have taken some amount of effort to get the SOT89 variant and secondly it is yet a robust and well-functioning replacement in this case (fitting pinout and leads, no thermal or mechanical aspects to be considered).

The other capacitors on my 01/W were apparently in a good condition, so I would not estimate this to be a general case of „bad-caps-alert“ for all the other 01/Ws around. However, in the recent past I read about 01/W owners on the net who have asked for advice on their whatever natured „no sound“ problem, and so this article may give you a hint towards the possible cause.

Update (October 07, 2008):

J-man sent me photos of his „no sound“ repair on a 01R/W, the rackmount variant of the 01/W. He writes: „I’m sending you the pictures of my fixed 01R/W, before and after the repair. […] I’m sorry about the quality of the pictures before the fixing: they are quite blurred, expecially one of them.“

235 Responses to “Korg 01/W „no sound“ repair”

  1. Peter sagt:

    Hello Hajo,

    vielen Dank für die super Anleitung. Ich habe heute auch meine 01/W reparieren können.
    War das gleiche Problem. Ich mußte zwei Elkos und zwei Widerstände ersetzen.

    Die besten Grüße,

  2. Anonymous sagt:

    Excellent work & a really effective help to everyone…!

  3. Sam sagt:

    Thanks for all of the info. I also suffered the same problem on my 01W. No sound first, eventually no display. I found other websites that claim solutions, but you have it right on. It is caused by bad electrolytic caps, google search „leaking electrolytic capacitors“. All of the electrolytic caps bearing the same mfg. in my 01W leaked. I changed every one on the circuit board, got my display back but still had no sound. I used it as a midi controller for a couple of years until I found your website. I changed the voltage regulators like you did but still did not have any sound. I checked every trace and component that the electrolyte leaked onto. I later found it to be R142 and R143, right next to the regulators. Service manual says they are 20 ohm fused resistors. Very hard to find unless you are buying thousands of them. I ended up using 20 ohm resistors and it has been working fine for the past 3 months. Money and time spent after seeing your site: The regulators 10/$1, Service manual $15 on ebay. Resistors from radio shack and 2 days of work. A local service guy wanted $500++ to repair. If your 01W has no sound, and no display, open it up and check for leaking E caps. If there is no sound, check the area near IC52 & IC53.
    THANK YOU HAJO for helping me fix my 01W

    • Sam sagt:

      I forgot to mention, I got the voltage regulators from ebay, and all of the electrolytic caps from Mouser electronics (www.mouser.com). They had all of them, even the NP (non-polarized) ones (8) near the output section in addition to the regulators. They dont have minimums like others. Hajo & Mouser are the best!!!

  4. j-man sagt:

    Hi Sam and Hajo. My 01R/W was lying silent and dead in a flight case, since I found this web page… I opened it up and immediately found 4 broken capacitors, with lots of electrolyt all over the printed circuit. I see that there are some other components that suffered severe corrosion: a couple of polyester capacitors and a couple of resistors. There is no way to see their values, of course. Tomorrow I’ll check the board carefully to see if there are other damaged components. I tried to find the service manual on eBay but I didn’t find one yet. Do you have it in PDF format, and would you sell it to me directly ?
    Thanks in advance for your attention. You both did a fantastic job, and I hope to follow your steps and bring the 01R/W back to life. Nuff respect :-)

    • j-man sagt:

      Well, after a couple hours of work my 01R/W is fully restored in perfect shape… and it sounds better than ever ! OK, maybe it’s just my imagination.. :-)
      Anyway, I replaced the 5 exploded capacitors: C100, C101 and C110 by the power supply 5-pin plug, C29 and C30 by the audio output. All of them were 100 microfarad/16v: I decided to raise the tolerance of the new ones to 63v (C100-C101-C110) and 25v (C29-C30). I measured all the other capacitors on the board, and they seemed OK.
      I had to replace one of the 22 ohm fused-resistors mentioned by Sam, R78, because it was burned by electrolyt. The smaller I found at home was 1/8 W… It’s a bit squeezed between the caps, but it works…
      Of course I carefully cleaned the board: luckily enough just a few traces were damaged and it was easy to restore them.
      Now I just need to know the value of C102 and C103, the small polyester capacitors in parallel with C100 and C101. I guess that 10nF should work, anyway if somebody could check the service manual and tell me about… Thanks in advance.
      I’m so happy to have my 01R/W back again, for a number of reason: you couldn’t imagine how grateful I am to you guys. THANKS A LOT !

      PS I shot some pictures after and before the job: if you’re interested please let me know.

  5. Hajo sagt:

    Sam and j-man,

    thanks a lot for your positive feedback and the detailed additions you gave with it. Your knowledge is welcome, and it will definitely help and motivate other 01/W users to get their boxes back on track.

    Please send me your pictures and maybe personal information via email to 01w[at]kessener.net if you agree to have them published here on this site. This also applies to external links to your website(s).


  6. Frank sagt:

    I am having the same problem with my Korg 01w. My keyboard has been laying dorment for several years. Everything works except no sound coming out. I took it to one repair place (Sam Ash actually sends their keyboards there to get fixed) and they told me it’s almost unrepairable. To get parts for it will be very difficult and expensive and will only result in the same problem eventually. From what I’ve heard, Korg used certain capacitors in the 01w which cannot handle the heat and over time they explode. So part of what this guy is telling me is probably true but now I found this site and see that some of you had no problem fixing it on your own. Unfortunately for me, I have absolutely no knowledge or skills to even think about attempting to fix this problem. I’m from New York. Does anyone know anywhere or anyone I can bring my keyboard to, to get fixed. I was actually going to throw it out a few months ago and held off because I just couldn’t imagine throwing out something I paid over 2 thousand for. This site has given me some hope, if I can only find someone with enough know-how to fix it for me. Any help will be appreciated. Thanks.

    • Sam sagt:

      Frank, I’m in NYC. I had taken my dead 01/w to Rogue and they wanted $500 ++ to repair several years ago. I too was gonna toss it out but couldn’t do it. Thanks to Hajo and this site I didnt. I am an audio engineer and owner of a sound company. I can but dont repair equipment because of the time necessary for troubleshooting. I will send my email to Hajo and maybe sometime after this 2008 year, (I am booked til the end of the year) I can help or guide anyone in NYC what I had done to my 01/w.

    • Sam sagt:

      One more thing, My repaired 01/w has been working flawlessly since my repair. Only problem I have now is the „clunk“ from worn out felt under keys. Does anyone know where I can get replacement felt? or know the exact thickness it should be? I’ve seen replacement felts for keyboards and read that thickness will affect the action and velocity of the keys. Thanks

    • Frank sagt:

      Let me just say, It ALWAYS pays to get a second opinion. After the repair place (that Sam Ash uses to fix keyboards), told me that my keyboard had capacitors which leaked and was basically unrepairable, my keyboard has sat in my house for two years untouched. Last week I was going to throw it out, but for some reason I just couldn’t bring myself to doing it and I went online to do more research on this problem and found this site. Now I don’t know why I didn’t think about this in the beginning, but I then went to the Korg website and found a listing of Korg repair people close to my location. I called one up, brought the keyboard over and in 5 days it was fixed for just over 200 bucks. The real kicker was that the problem I was initially told, was not the problem. I had no leaking capacitors. I forgot what it was, but something broke inside that usually happens when you don’t use the keyboard for awhile and its left in a damp area. That is exactly what happened. I didn’t use it for about 6 months and was kept in my basement. One day I decided to use it and everything worked except no sound coming out. Just to think, I was going to put this out by the curb and throw 2500.00 dollars into a garbage truck. The keyboard is as good as new and sounds wonderful. And I’m also just remembering that those scumbags at that initial repair place charged me 40 bucks just to look at it. Anyone having a problem, it may be worth going to the KORG website and looking up local KORG repair people. They obviously know these keyboards better than anyone else. I’m proof of that. Thanks for responding Sam.

  7. freshman sagt:

    I had the „no sound“ and „sticky key“ issues with a 01/W. searched the web a lot and found Hajo’s blog. the name was familiar to me, so i decided to ask the one i had in mind. and yes, it was Hajo. we live in the same town. :)

    talking to him, made me replacing two elkos but still no sound. he then took a look on his workbench at home and found a tiny smd resistor next to the elkos. replacing it (R142 / 18 Ohm) and the elkos i used (35V – i was replacing the originals with 16V first) – the 01/w made sound again.
    while half the device was partly apart, i decided to go on.

    next was the keyboard, removed all keys, cleaned them, used hajos „Klüberpaste“ and refitted them. as said by a comment above: its strongly adviced to remove the „activator strip“ – at least, before you remount the single keys. its only 10 screws, but you wont risk demaging any of the metal-tongues of the „activator board“ – i underline this hereby :)

    next step was removing the key/lcd-panel. here its adviced to remove the huge metal-bar which sits partly under the psu. you have to partly unscrew some screws from the psu-holder – not totaly unscrewing them, just a bit so you can elevate the psu and remove the metal-bar quiet easily ( 5 or 6 screws on the psu, IIRC ).

    next step was cleaning the key-pcb from dust and while thinking about using chemicals or replacing any key, we decided to replace them all.
    afterwards I did connected the key-pcb to the mainboard and connected the display, to check, if all keys are working as expected. and yes, it was worth replacing them.

    Next one: the lcd backlight. hajo ordered 2 panels, but unfortunatly one of them was defective – no light at all. the second one was working properly.
    the good thing here: after unsoldering the back-light from the two soldering points, we were able to just drag the backlight out of its housing ( gently try to pull it out, a lttile bit forth and back ) – it was partly glued to the lcd-pcb. nothing got damaged. this way we didnt had to fully taking apart the lcd.

    after fitting the new backlight and soldering it, we did a test, and there was light. no problems with any pixels, just perfect, i’d say :)
    the reassembling took a while, but using photos i made while disassambling, i had a good orientation and could place all screws on its original place.

    i also made some sketches of the postion of the screws on a paper – on each step: undersite, main-pcb, keyboard, key-pcb, activator-strip and -activator-pcb, lcd. placing the screws around the sketches on a free table. this was very helpful, when reassembling the device.
    last update was the firmware. hajo got a capable burner, so the 01/w was refreshed from #31 to #62.

    one last note: good tools are essential. starting with good screw-drivers, a desoldering-iron ( incl. some desoldering wire ), a good solder-iron/station.
    Finaly I have to say, without this blog i never ever would have gone so far; maybe i should mention, the device isnt my own, a friend left it here, when he moved to another city; but i told him what happened meanwhile :)

    Well, lucky enough to have hajo around. thats for sure a plus. a big plus.
    thanks again, Hajo.
    Taking care of the steps described at this blog and some basic skills in handling electronic parts makes it possible for you too :)

    as said above, i made some pictures and told hajo about them, so he might use them in some sort of gallery here. hope they will help you too.

    best ragards.

    • Hajo’s » Blog Archive » Freshman’s 01/W refurb sagt:

      […] following is a set of photos from Freshman’s 01/W refurbishment. In fact, his 01/W suffered from the “no sound” syndrome, the […]

  8. andy sagt:

    hey frank,
    you said „something broke inside that usually happens when you don’t use the keyboard for awhile and its left in a damp area.“ my audio outs have also conked out after sitting in a basement for a while: can you elaborate on exactly what broke in your case so i can look for it?

    thank you.


    • Frank sagt:

      Hi Andy,

      I do not know anything about electrical stuff so when this guy was explaining what happened to my keyboard and what had to be fixed, I had no idea what he was talking about. At the time I didn’t care, I was just thrilled that it was fixed and I didn’t throw it out. Looking at my receipt, he wrote on it „Repaired open layered traces.“ According to him it was 2 1/2 hours labor and it cost me $216.00 dollars. I don’t know if that explains anything for you. What I do remember him saying is that this usually happens when the keyboard is not used for some time and is left in a damp area. That explained everything for me because there was one summer where I had my keyboard in my basement and I wasn’t home for weeks at a time because I was working on my vacation home. Therefore there was no dehumidifier going and I actually started to get mold down there. This guy told me that even if you don’t have the time or feel like using it, to put the keyboard on for a bit, once in awhile. I don’t know where you live, but this guy I got from the Korg website. The name he’s under is Santorelli Prof. Electronics 102 Park Ave Bayshore, NY 11706, [edit: phone number removed by Hajo]. Hope this helps you. Good Luck!

  9. TJ sagt:

    I’ve got an 01W/R. The display screen works, but is too dim to use on stage….repair shop says the whole display needs to be replaced….special order….expensive…any ideas?

  10. S.D. sagt:

    Hello Hajo.

    Thank you for your site and your efforts.
    I was wondering if you can help, or at least guide me in a right direction :)
    The problem is with my Korg i2.
    I left it on. When i got back to it whole power line was down.
    Since then, when i’m powering it on – LCD screen shows the logo, with a crossing horizontal line (each time line appears in a different place) and inage dimms away, while backlight stays on and the keyboard is working correctly.
    It’s also possible to see what’s on the screen, under the sharp angle.
    I’ve been told that this problem might be caused by a simple replacement of a capacitor, responsible for the image stabilisation.

    Anyway, I would apreciate any comment on this problem.

    Thanks in advance

    • Hajo sagt:

      Hi S.D.,

      although I’ve not yet experienced the behaviour you describe, it sounds as if the problem is located on the LC display itself. Check the capacitors on the LCD’s circuit board, see the following link for reference:

      Blown cap on LCD of Korg 01R/W

      Have a look at the other capacitors on the mainboard as well.


      • S.D. sagt:

        Thank you for reply, Hajo.
        I hope you had amazing holidays :)

        Back to the problem…
        Surprisingly, capacitors on my LCD board looked exactly the same as at:

        I’ve replaced the „burned“ (right) one but it didn’t help.
        I’ll try to replace the second one (which looks fine), hope it will help.

        In addition to that, i forgot to mention, that i have a weird „whistle“ sound coming from the power supply.
        I remember this sound (it was barely noticeable), even when keyboard was operating normally, but now it’s very loud.

        • Hajo sagt:


          the „whistle“ you describe is the sound of the inverter that generates the AC supply voltage for the EL-foil (the backlight) of the LCD. The inverter is located on the power supply unit on some Korg instruments. There’s always some noise around ~400 Hz with this type of inverter, but when it starts to audibly „whine“, this is indicating a high load due to the dying backlight; the backlight will also be dim in this situation. I would recommend to replace the EL-foil, see this article for photos.


  11. Donal sagt:

    Apologies if this is off topic, but I cant see other sites where my problem might get a reasonably sensible answer!

    I have a Korg M1 and all outputs including the headphone output, sound distorted. The distortion is not constant, but stays for about one second after the key is pressed. It sometimes returns but not always.

    Anybody have any ideas as to the cause? I’m aware that it’s an old keyboard and that parts are likely to be difficult to come by, but it would be good to know what is required to fix it.


    • Donal sagt:

      OK…a bit more info….it’s not the D/A PCB. I swapped the one from my M1R (which are both the same) and had the same result…the M1 is noise, the M1R isnt!

      My own feeling is that this might be a preamp problem….basically, that the preamp is hitting whatever it’s given at 100% and therefore ultimately distorting…..OR whatever is going to the preamp is at too high a voltage, thereby causing distortion. When the sound decays to a lower volume, the distortion reduces. Just my own musings, mind you…nothing really to back it up…..

      Oh….dont all rush to help! ;-)


    • Hajo sagt:

      Hi Donal,

      as you’ve already dared to swap boards, I’d recommend to check the +/- supply voltages on PSU output and op-amps. If possible, try to monitor voltages when distortion occurs.


    • Donal sagt:

      Hi Hajo,

      Thanks for the reply. I’ll try that and get back to you on it.



    • Hajo sagt:

      Hi Donal,

      I just had a look at the M1 service manual and noticed, that there’s an additional active (op-amp) stage on the output connector board KLM-1262 behind the D/A board. If the power supply is ok, then the error is likely to be found on this output board. Drop me a line, if you need the schematics.


    • Donal sagt:

      Hi Hajo,

      I’ve had a look at the +/- voltages on PSU, and I get 11.7v each side regardless of whether it’s distorting or not. I also had a look on the 1261 and 1262 PCB’s and I get no variation from 11.7v. While i was at it, I removed the 1262 PCB for a visual check…nothing obvious to be seen…no popped capacitors or dry joints. In fairness, this keyboard shows no signs of having been gigged or otherwise given any kind of rough treatment.

      Am I wrong in that I’m beginning to think that the distortion is probably eminating from the synthesis side rather than from the amplification side? I have an older, more worn (but working!) M1. I’m wondering if I should start considering a heart/main board transplant?

      Thanks for your continuing help!


    • Hajo sagt:

      Hi Donal,

      one idea fom my side, before you start transplanting mainboards: hook an amplifier on pins 4..7 of CN13A and listen to the audio. If all four signals sound distorted, even if you disconnect CN13B, and if both 1261 DAC-boards behave the same, you may not be wrong with your theory. It would then still be interesting to find out, what is going wrong on the mainboard.


    • Donal sagt:

      Hi Hajo,

      I hooked up an amp on pins 4-7. Only 4&5 had signal as the program I selected was only programmed to output on A&B, but both were distorted. I disconnected CN13A (it was easier to reach and would, i assume have the same effect as disconnecting CN13B) and there was no change.

      Would a small audio file of a couple of piano notes be of any benefit in trying to diagnose the problem? If so, send me an email and I will reply, attaching it.



    • Donal sagt:

      I think I’ll give up on this and send the m1 to Korg for repair. .

      I’ll let you know what the problem was when I get it back!


    • Simon sagt:


      I do have the very same problem. I’m not skilled in any electronics stuff but friends are… now I would be very happy if you could drop a line on what the problem really is.

      I bought mine off ebay and the problem came up after a couple of days, at first it worked perfectly.

      I hope Korg still has M1 repair, maybe there’s even a simple solution…

      I live in Switzerland, hope I don’t have to ship my M1 around the world for that repair…



    • Donal sagt:

      Hi Simon.

      My M1 was delivered to Korg UK on Wednesday 29th. I expect to hear from the shortly and I will post any information I get here.

      Before I sent it, the repair person in Korg said that main boards are not available any more, but that it may be possible to repair the board at component level.



    • Simon sagt:

      Thanks Donal!

      I hope it’s not the Mainboard… That would be 250 $ thrown out of the window for me then…



    • Donal sagt:

      Hi Simon,

      I just got the quote from Korg. It says „To strip and rework pcb, dry joints found on DAC PCB and main PCB.“

      The cost is £60 plus carriage of £31.88 so including taxes the total comes to £105.66. As I live in Ireland, I think that this is quite reasonable. I actually sent the keyboard via post from Northern Ireland so that only cost me £23.

      People tend to complain loudly when they do not receive good service, but in this instance I’d like to give Korg a thumbs up and say that I’m very happy with the service I’ve received. It’s been prompt, polite and efficient. Well done all.


    • Hajo sagt:

      Hi Donal,

      thanks a lot for your feedback and information, much appreciated, and also thumbs up for Korg and your decision to send your M1 for repair.


  12. samuel sagt:

    where can i get those small chip capcitors from
    and what is the capcitance value? c21, c19,r243, r142

    • Hajo sagt:


      the parts are available at electronic stores. C19/C21 are 100nF, R142/R143 are 20 ohms fused resistors, which were hard to find for me, so I replaced them with standard SMD resistors. Btw: You may get the schematics from the 01W group’s download section on Yahoo.


  13. James Knight sagt:

    I’ve got a loud annoying high-pitched whine coming from the PSU of an O1/W Pro. It seems like that’s probably the backlight issue, so I figure I should try replacing the EL panel.

    Do you have any recommendations on what to purchase for a replacement EL panel? I’d rather not take the whole keyboard apart twice — once to figure out what’s in there, and once to replace it — if at all possible. :)

  14. Damien Coutrot sagt:

    I’ve got the same problem with the M1.
    The sound is distorded. I Wan’t to check the sound just after the DAC but I’ve no service manual.

    Some boby can send me that ?


  15. Trung sagt:

    I’m look around the web and find this place. I read some up messages in here, it’s very good information. But can not find schematic for Korg 01W/FD. I need help with Service Manual or Schematic for Korg 01W/FD so I can repair it. Anyone has service manual please help me.

    Here is my email: [edit: removed by Hajo]

    Thanks a lot in advance

    • Hajo sagt:

      Hi Trung,

      the service manual is available at the download section of the Korg 01/W Yahoo group.


  16. BigBillKahuna sagt:

    HELP!!!! Just finished installing a new backlight. Works fine except that there are no numbers displaying….just a beautiful , bright green glow! Also (even worse), I get no sounds.
    I thought I was very careful about re-installing everything, so I’m really concerned that something else crapped-out. Guess I’ll have to dis-assemble everything all over again. Sigh……….
    Anyone have any thoughts?

    • BigBillKahuna sagt:

      O.k……a lesson well learned. Turns out I forgot to plug in a multi-pin connector! I guess after 7+ hours of benchwork I was getting a little impatient.
      My thanks to Hajo and all the posters here who enabled me to undertake this project.
      I purchased the backlight from Telesis, P.O. Box 19015, Anaheim Hills, California, 92807 U.S.A. for $35.00 which included a pdf instructional cd.

      • Hajo sagt:

        Hi BigBillKahuna,

        thanks a lot for your feedback and clarification. All the best to you and your Big Kahuna Band.


  17. Jim Owens sagt:

    Hello, Hajo! A friend has asked me to look at his Korg Pa-60. No sound. I’m just reporting this in case anyone else has similar problems with a pa-60.

    The midi out works fine. This model has external audio inputs, so I can confirm that the amp and speakers are working OK.

    The I/O board has plenty of garden-variety electrolytic caps, and no visible problems. It’s connected to the rest of the unit by four cables. One sends signals to the power amp. Another goes to the panel volume controls. The remaining two are ribbon cables from a board encased in a steel shield, which I infer is the „main board.“ One of the ribbon cables is from the „main board digital“ and feeds the midi, which as I said is working fine. I scoped the signals at a nearby 7404 and I can see digital activity when I press a key.

    The other cable connector is marked „main board audio signal.“ The connector has 20 pins. (I don’t understand why you’d need a 20-pin ribbon cable to carry audio signals.) One of them has a steady AC signal, regardless of whether a key is pressed, and the others don’t show any activity on a scope. A couple of them carry DC.

    Presumably the main board power is OK, because the midi is working. I took the shield off and looked around, but I couldn’t see any obvious problems. Almost all the caps on this board are uniform in size, rather squat, flush to the board, and encased in shiny metal with one side painted black.

    Just reporting in, although of course if you have any advice I’d love to hear it.

    • Jim Owens sagt:

      I have the main board out again. On the underside are four large proprietary chips labelled „BANK0H, BANK0L, BANK1H, BANK1L.“ Each of them has a whitish bloom at one end. The bloom also appears on the PCB, and under high magnification I can see dark blotches on or around the traces. Humidity damage does seem to be a possibility. Redcall that the board is encased in an envelope of solid metal, so it wouldn’t breathe well.

      Is it advisable to clean this off with isopropyl alcohol for a better look, or should we just take it to a specialist as is?

    • Hajo sagt:

      Hi Jim,

      the 20-pin ribbon cable: does it transport analog or digital signals, and where did you locate the DAC circuitry?


  18. Jim Owens sagt:

    HI. I no longer have the synth. I did clean the suspicious-looking parts with rubbing alcohol, most of it came off. The tracks appeared to be intact; I double checked with an ohmmeter and they seemed OK. But this did not revive the sound. I had to reassemble it to find this out. After I got the unit back together, I thought I might as well just return it to the owner. There was nothing simple and obvious that I could do, especially without a schematic.

    I wasn’t reading any signal at all on most of the 20 pins. You’d think they’d carry digital, but the circuitry on this half of the destination board (the IO board — the other half is MIDI circuitry) consisted mostly of clusters of discrete components and a couple of 8-pin ICs — more what I’d expect to see in a preamp. That’s what puzzled me. Maybe that’s all you need for a DAC though — I’ve never worked with them.

    Thanks for the reply!

  19. Tim sagt:

    hi Hajo,
    thx for your infos. a few days earlier i got my 01w/fd repaired (the stick keys), and after that i found the ivory key on the rightmost doesn’t sound anymore. can u figure out the reasons?? thx a lot.

  20. Aykman sagt:

    Hi guys, I nee the service manual for 01/W and 01/W pro X. Can someone point me in the right direction or [text & links removed by Hajo]? My 01/W pro X died last week and I need to repair it……help is apprectiated regarding service manuals. Thanks in advance for any hint. Nice blog……….!

  21. kyzee sagt:

    hello hajo, i am a korg 01/w user and looking for help to repair the unit. right now i am facing problem with the sustain/damper pedal not working. I undersand there is an ic controlling the damper switch. do you know whece can i get the parts for that? thks in advance.

    • Hajo sagt:

      Hi Kyzee,

      how or why do you suspect an IC to be damaged? I’d recommend to check the obvious first, which is the pedal itself with cable & plug and also the DAMPER jack and respective soldering joints.


  22. Sparky Montoya sagt:

    I just turned on my Korg 01W pro, which was sitting in the garage for about a year. It was working just wonderful and then i hear a „pop“. What can that be. I have turned in on and off, tried different cables, re’inialized it and still no sound. I tried headphones and that doesn’t work. I live in Dallas Texas. Is there a repair place that can fix it or maybe I can if pointed in the right direction. I have only used Korg for the past 25 plus years and will stay loyal.



    • Hajo sagt:

      Hi Sparky,

      sounds like you witnessed the death of resistor R142 or R143. Have it fixed by a trustworthy technician.

      All the best,

  23. Aykman sagt:


    me again. So, my Korg 01/W pro X is working approx. 5min without problems but after that slowly distortions appear until I have very loud noise & distorted.

    I am planning to open my Korg after 24.Dec and check for leaky caps and damaged parts.

    One guy told me that hissing sound (distorted sound) can also be caused by the faulty E-Foil or damaged FD Drive? I do not really understand how the FD drive can influence the sound?

    My other questions is: Did someone update the DA Converter by Korg service? What improvements did you get? Or is this part of the ROM update?

    Thanks for any answer :-)



  24. Peter sagt:

    Does anybody have the exact part number of the „fused resistors“? Or what is the „german“ term for it?

    • Hajo sagt:

      Hi Peter,

      the german translation is „Sicherungswiderstand“. My search for a replacement part ended with the conclusion, that SMD type fused resistors are expensive and/or only available in large quantitites.


  25. Angel Sing sagt:

    I own a KORG 01/W ProX, I am only interested in one sound and one sound only and that’s the Grand Piano sound. The guy I bought it from programmed it with a bunch of layered voices and I can’t figure out how to remove all those layered voices, I’ve tried downloading to users manual and I tried resetting it back to the default settings, back to how it first left the factory, but I am totally clueless. I can’t even find the Grand Piano voice, I’ve looked in both banks A & B, but out of 256 voices or however many voices there are I just didn’t see Grand Piano, but I have a feeling it’s hiding in there somewhere. So, please help me with my KORG 01/W ProX – please. Thanks.

  26. Paul sagt:

    I need to replace the R78 of my 01/RW. It’s a 22 ohm one? ..or I’ve better to take something else?

    best regards!

    • Hajo sagt:

      Hi Paul,

      18 or 22 ohms should both be an appropriate replacement, as the original value is 20 ohms.


    • Paul sagt:

      thanx a lot Hajo! ..at last one question: the small polyester capacitors C102 and C103 with 0.1µF (in parallel with C100 and C101 .. just look up at the posting from j-man @ his 01/RW..) ..: how many votage they shoult have? ..also around 25V like the C100/101 with 100µF?

      many thanx!

      • Hajo sagt:

        Hi Paul,

        the original part is a „standard“ 100nF ceramic capacitor, usually ranging up to 50 volts or more. It seems that J-man replaced it with polyester types because he didn’t have any other parts at hand. The maximum voltage is much less critical than with electrolytic capacitors, 25 volts or more will be perfect.


  27. Fran sagt:

    I had my 01/Wfd for 17 years and never had a whine until I replaced the entire LCD backlight last year. I even tried the „reverse polarity“ trick with no success. Should I replace the inverter?

  28. Gleb sagt:

    I have same problem with my M1 as Donal last year. Distorted sound. Have already changed both C66 and C67 cap’s and IC14 and IC15 Integr.Circuits because they was covered with electrolyte. Contact between 6 leg of connector CN13A on the KLM-1261 was burned out. reconnected it. no changes, steal distorted sound, no sound on left channel in headphones. when pressing the keys stronger the LCD starts to light also stronger.

    any ideas? thank you a lot Gleb

    • Hajo sagt:

      Hi Gleb,

      no ideas, at least nothing precise, sorry. Sounds like a combination of errors, and you will have to isolate them one by one. I would start with a deep visual inspection of the mainboard and check of the supply voltages, then go on with individual parts like diodes, capacitors and resistors (as far as possible in-circuit) and traces. If this does not bring up any results, maybe ask KORG service for assistance or bury the M1.


      • Gleb sagt:

        Thanx Hajo,

        all clear. where can i find a service manual to know supply voltages?

        one more thank you.


        • Hajo sagt:

          Hi Gleb,

          the schematics are not required for a basic inspection; start from the PSU and follow the wiring and traces. Voltmeter, continuity tester, ohmmeter and diode tester will do most of the job. If still required, do a web search for the service manual.

          Good luck and regards,

  29. blob sagt:

    A few years ago my M1 developed excessive hiss on certain patches ( more noticeable with certain effects e.g. the exciter ). Even the unaffected ones now decay into a fuzzy sounding hiss as they fade out. The sound also seems to have lost its warmth.

    Is this the distortion described in the m1 posts above? Wish I knew how to fix it :-/

    • Hajo sagt:

      Hi Blob,

      to me this sounds more like this story. However, the capacitors on your M1 may be worth an inspection.


  30. Gleb sagt:

    Hi Hajo,
    want to shaw you pic’s of my PSU. most of caps have weird substance around. is it electrolyt? how can i upload the pictures?

  31. joe sagt:

    I have a backlight problem and will need to order Q1, 2SC2785 transistor and TA-042 filter choke.
    These parts are on KLM1530 power supply board. Also, I need the parts R142 and R143 they are 20 ohm chip resistors located on the main board.

    Do you know where I can get these parts. I am rebuilding my Korg 01w Pro.



  32. gabriel sagt:

    To anyone that can help me I’ll thank in advance.
    I have a korg 01w not fd. I bought some pcm cards and inserts them and
    press button for cards to read and no luck, the button does not even turn
    on at all. I try going to global and disable the protec. and still
    no luck. Can any one out there tell me where or Im doing wrong?
    Thank you.

    • Hajo sagt:

      Hi Gabriel,

      the PCM cards contain new waveforms that can be selected in program edit mode only. The INT/CARD switch refers to the COMB/PROG/SEQ data card that originally came in a two-card set with each PCM card. See this link for reference.


  33. Alan sagt:

    Hi Hajo,

    I have an 01/Wfd that I got in ’92. Over the years it’s been developing little problems but still worked overall. The other day it said „low battery“ so I decided to change the battery. While I had it open I decided I would try to fix some of the other problems. Basically I took it all apart and cleaned the keys, fixed a broken output jack, loose joystick, 2 broken keys. When I put it all back together, it won’t power up at all. Either I did something wrong, or a component has failed in the process. Too bad, cause it was working before and now I’ve fixed a bunch of mechanical problems. All the caps look ok. Any ideas on what went wrong? Thanks

    • Hajo sagt:


      sorry for the delay. If your 01/Wfd is not already working again, ensure that all connectors are properly plugged in and that no loose screws or parts may produce a short. Check fuses on the PSU and supply voltages.


  34. Jonah sagt:

    I have been having a loud, mid pitched buzzing from all audio inputs. I think the problem is then in the power board. I checked everything very thoroughly and the only problem that I can see is that two of the legs on CN4B have been soldered together. Would that cause a buzzing sound, or should I check my caps (which LOOKED fine)? Or might it be something else.

    • Hajo sagt:


      sorry for the delay. The 01/W does not have any audio inputs. If it is the 01’s audio output that you meant, then start with checking the +5 and ±12 Volts lines coming from the PSU. If everything looks right, I would indeed recommend to check the caps (visual inspection, capacity, ESR).


  35. peter sagt:

    No sound , I see, not uncommon.
    I opened up the back, but every think looks normal. Will check next week with
    x15 magnify glasses.
    Does anyone know about the voltage ? Bought the 01wfd in germany, but are in the us now, have a converter. Does the korg runs on 110v as well ?

  36. Pieter-Jan sagt:

    Hi Hajo and J-man,

    Thanks to you I just fixed my Korg 01R/W! I had to replace the same 5 exploded capacitors as Sam did. No other objects were damaged. After replacement (done by a Radio/TV technician) I still had no sound and even lost my display. After measurements with a multimeter (by myself) I found that not all connections were made correct. I had to resolder some places on top of the print. After that everything worked fine! So for others who have to repair their Korg; you have to make sure that the contact is working BOTH on the top and on the bottom side. The 01R-W service manual was also a good help to me. For others, I found it here: [edit: link removed by Hajo].

    Again thanks a lot for sharing this technical Korg 01/W knowledge!

    Pieter-Jan (the Netherlands)

  37. Gloria sagt:

    Can anyone tell me the capacitor value of C1-C4 on the power board of the Korg O1WFD ? Power board part number appears to be KLM_1530B.


    We lost power to the keyboard and it appears that C2 is dead.

    Memphis, Tn

  38. vito sagt:

    Anyone know the value of Capacitor’s 97-100? (Korg 01w)

  39. vito sagt:

    Thanks Hajo! I wasn’t sure, because the schematics don’t say (if it does, I can’t find it) and J man stated on Oct 5 that he used 100 Micro F.
    Thanks a bunch!!!

  40. angela sagt:


    I hope someone can help me. My 01/wfd has gone a bit mad. The sound is high pitched hissing and distorted. I never lost sound like most of you did.
    I have changed all the know bad cap’s even through they where all still ok on the main PCB.The 20 ohm resistors are all still working. I replaced the two +- 5v regulators. I checked the 12v incoming and the 5v out going they are all there.
    I found one bad cap on the LCD that had leaked a bit (4.7uf 35v) so i changed both of them as well. (The lcd was still working) just no back light.
    I have also unplugged the FDD just in case that was the fault. But still i have the hissing and distortion.
    I have no idea where or what to look for next, I am handy with a soldering iron, but fault finding is not one of my strong points.

    Kind Regards

  41. Enrique L. sagt:

    Thank you. Thank you. Thank you.
    I replaced c95 & c96 since they had leaked.
    But still no sound. Replaced r142 & r143 with 20 ohm radio shack parts……. SOUND, beautiful sound.
    May go after dim display next, but no hurry.

    Thank you all again.

    Enrique L.
    Simi Valley, CA

  42. Bab sagt:

    I have the same problem no Sund,display Show´evrything but no sund,
    I have just change The batteri and now there is no sound,så if you can hjällp mej,

    • Hajo sagt:

      Hi Bab,

      to me this sounds like the typical problem that is described in the article you refer to. Replacing the battery is not the solution, instead you should inspect the mainboard or rather the voltage stabilization circuitry around IC52 & IC53.

      All the best,

  43. Bojan sagt:

    I have problem with my 01/wfd. When i turn on the LCD shows nothing except light. The buttons like combi prog seq are flashing red as usual. But there is no sound. I opened too check for capacitors and something unusual but i found everything ok. I disassembly the synth and reassembly but again no sound and LCD’s light is just working.I went to local electrician and he measured something at power supply but he said everything is ok with the power supply. Here’s picture. (sorry for the bad quallity. And the LCD’s light is working but you cant see from the light in the room.)

    [edit: link removed by Hajo]

    • Hajo sagt:

      Hi Bojan,

      is there any reaction when you press a button, i.e. when switching from COMBI to PROG mode? If not, then the CPU respectively the „OS“ is not working. I would still recommend to thoroughly check the PSU again, then wirings, capacitors, oscillator and EPROMs. Sorry, no distinct and quick help possible from afar.

      All the best,

  44. Singing Cat Jim sagt:

    Hi Hajo & J Man,

    MANY thanks for your repair advice & the excellent photos..I have a M1 and a 01W/fd and the 01 decided to fail last night with all the symptoms you described in the article…sure enough, the caps around the regulators were blasted and one 20ohm o/c..the tracks were ok though (after the spot-on advice regarding cleaning the PCB with IPA)-Unfortunately, I ‚lost‘ all my sounds, but this was ok as I had only 20 variants on the factory patches and brought them back within an hour or so.
    On thing that did happen to my 01 that your readers may want to know about-when I first got it about a year ago, it appeared dead-no display and apparently no power-checking the main -/+ rails showed them to be ok, as were (at the time) the Sub-PSU voltages on the main board!..having had a load of repairs in that month, I shelved it until I had more time for a diagnosis-when I did get back to it, it was to remove the main (and now known-good) PSU to try & resurrect a client’s 01 and prove it was their PSU that was defective (it was an as-u-wait repair!)…before I took out the supply, something told me to power up the 01 with headphones in and Lo!..It WORKED…but only for about 30 secs after which there was a BANG and smoke poured from the floppy-disk unit!
    Needless to say, I turned off quickly and disconnected/pulled out the (STILL-smoking) floppy-drive…The drive had failed due to the motor seizing and it appears that this had prevented the 01 from powering up properly or at all-once it was disconnected and out, all was well with the 01 until last night’s capacitor bang-party…Once again, thanks for the guidance you gave on this page as I have a gig coming up & really needed the 01 for it.

    All the best!

    Jim McKenna

    ps do you know of any Korg 01 librarian/editing software for the Mac that will run on either OS9 or other Classic OS..or at a pinch, OSX?..I have a cracker for the M1 from Spazztech that runs on OS9, but so far no luck on the 01 front.

  45. niclas sagt:

    hi i bought a korg 01/wfd with no sound and dimmed display and whining from the switched psu.got sound and resetted it thanks to this site .changed the 100uf caps (all)they have puffed themselves. and a resistor in the near by of 7805 voltstab.found the one of the caps behind the display also puffed.
    now i wonder if u have a clue what i should look for i a yamaha QY-20 jam/musik maker/arranger.the display just went blank under a session but sound is still there .the only life on the lcd display(no backlite) is a line when i shut it on,then dissapears.

    • Hajo sagt:

      Hi Niclas,

      congratulations on your successful 01/W repair and thanks for sharing the information. Concerning the QY-20: Sorry, nothing precise, just the usual recommendations and procedures: visual inspection, checking supply voltages and wirings. This should help at least to narrow down the problem.

      All the best,

  46. John sagt:

    Hi, Does anyone have the PN’s and website to order the parts for:
    IC52 and 53, R142 and 143 and DT2 and DT3?


    • John sagt:

      Forgot to ask, what should I check for when the 01 WFD stays on the LOGO or startup screen? The only I can get it to display is the ROM version, but it does nothing else.


  47. dany sagt:

    hi this is when encendes korg synthesizer and music workstation korg screen says and is just like that and does not sound keys??

  48. John sagt:

    would anyone possibly have a main board for the Korg 01 WFD in working condition for sale?


  49. joey jno-lewis sagt:

    seemed like my o1w 5 pin connection to the circuit board has messed up…. after repairs to the transformer …. i need to know what voltage each of the 2 red, 2blue and 1 black wire (guess 0 for ground) carries

    • Hajo sagt:

      Hi Joey,

      you will find the 01/W service manual online with a „g-search“ for „korg ta-040 transformer“. Please also see this site.

      Hope this helps,

  50. Jorge Aristondo sagt:

    Please anyone would help me??
    i already fixed the display problem i had with my 01r/w
    Now i have no sound..
    Headphones or outputs got any..
    do i fix this by just changin some caps?? if so wich ones?

  51. Arjan S. sagt:

    Hi Hajo,

    I’ve also attempted to fix a 01/W FD but mine was actually doing nothing at all on most boots. Some boots was fine. I got the backlight repaired and replaced many caps but cannot get the unsuccesfull boot problem out. Repair guy said it was a memmory problem, but I’m not very confident in him. Anybody had a similar issue and got it fixed ?


    I have some pics of the operation. You can use them if you wish for clarification. http://www.audiodude.nl/?p=673

    • Hajo sagt:

      Hi Arjan,

      no instant ideas. You did a lot of good and reasonable work. I would recommend to try another set of EPROMs as the next step. It is rare but not uncommon that these become error-prone and lead to a strange behaviour. Great website btw, worth reading!

      All the best,

    • Arjan S. sagt:


      Last time I replaced eeproms was on a TBS Pinnacle soundcard… You are talking about the VUK 01 HIGH and LOW ones right ? http://www.audiodude.nl/wp/wp-content/uploads/2012/04/Mainboard-1.jpg Where would one order pre-programmed new ones ? Korg directly…? I haven’t got one of those programmers…


    • Arjan S. sagt:

      I’ve updated the EPROMS some time ago (thanks Hajo) but still no luck. However, it seems that I will get it to work if I leave the unit on for like half an hour or so. Does that ring a bell ? anybody ?

  52. Steve Jones sagt:

    Just wanted to tell you my church has a 01-Wfd which stopped working some time ago and had been sitting in a storage closet for years before I pulled it out to take a look at it. It powered up and I got a screen display but no sound. I Opened it up and guess what? C95 and C96 were ruptured and had leaked. I followed your advise and now my church has a fully operational Korg 01-Wfd once again. Your site really helped me a great deal to fix this. I find it a little odd that it should be the exact same two caps that you had an issue with. Anyway, thank you again.

    • Steve Jones sagt:

      oops! I spoke too soon. Turns out that yes, the board powered up to the ‚initial‘ stage…. and that was it; still no sound. I cleaned the board with iso alcohol and swabs and removed all of the residue from the old failed capacitors and looked closely at the circuit traces to see if any were dissolved by the leaking acid. All looked good but still no sound. I’ll pull the board back out again and see if I might have missed something the first time.

    • Hajo sagt:

      Hi Steve,

      thank you for sharing your experiences. Please check the resistors R142 and R143; I would suspect at least one of them to be bad. You can check them in-circuit, the resistance should be around 20 ohms.

      All the best,

      • David S sagt:

        I tested these two resistors, because I had the same problem as Steve. I’m very new to all this. I got 143 to read about ~18 V, but 142 wouldn’t budge. Is that a component I can replace? There are no solder points beneath it on the board.

        • Hajo sagt:

          Hi David,

          your supply voltage is asymmetric, that’s for sure with -18 V vs. nothing, and this is bad. Which resistance do you measure for R142 and R143 in-circuit (with the 01/W powered off!)?

          All the best,

      • David S sagt:

        I should also note I used 25V rated capacitors as suggested, rather than replacing with the original rating

  53. Radek sagt:

    hi there!

    i have this terrible distorted sound problem. no idea what can be wrong. of course there was problem with c95/96. i’ve exchanged em with new ones. checked taces etc. exchanged r142/143 coz they were dead too. ic52/53 are fine and produce -/+5v. no result.

    started messing with effects section in sound editing. i’ve noticed when i set fx1 and fx2 to channels 1 and 2 outputs 3 and 4 sound very good. no distortion etc. when i manually set fx1/2 to off main sound is little distorted. when i set em to on position, sound is terrible. i tought it can be a problem with effects section in instrument.

    ive exchanged big ic17, ic43-50, ic35, ic34, ic25/26/28. but it still has same issues. maybe i’ve forgot bout sth? what can be wrong? what should i check?

    • Hajo sagt:

      Hi Radek,

      kudos to you for all the work and replacements you have done so far. It seems that you have narrowed down the cause of the problem to the digital domain, not the analog. Sadly, I don’t have any clue. It would be great if you could post your future findings and/or solutions on this repair.

      All the best,

  54. Mary Johnson sagt:

    I have a Korg sampling grand where the lower half of the „c“ keys do not play. I am not an electrician. Any ideas on how to fix?

    • Hajo sagt:

      Hi Mary,

      in my opinion only a technician can fix this. But it does not sound too troublesome to repair — probably a broken wire or a bad diode in the keyboard matrix. It seems that other SG users also experienced this malfunction, btw. Sorry for my late answer.

      All the best,

  55. Michael sagt:


    I recently got an 01/WFD on ebay, it had an issue that sometimes you powered it and the display would be blank and the keyboard wouldn’t produce any sounds, none of the function buttons were lit either. Turning it off and on again seemed to remedy this, it was fine, then the other day, I lost the left channel output and the headphone socket doesn’t work at all. Is it likely that this is the same area that needs attention? Also, I have an M1REX that doesn’t produce audio (other then incredibly weakly through the headphones turned full up) would this be a similar problem?



    • Hajo sagt:

      Hi Michael,

      problem #1 reminds me of Arjan’s 01/W, see this comment. Unresolved for him, afaik. In combination with the lost audio output as problem #2 on your 01/W, this however clearly guides towards the „no sound“ or „bad cap“ problem. Do a visual inspection of your 01’s mainboard. The same goes for your M1 — similar problem, I would say.

      All the best,

  56. Mars sagt:

    Hey, I had the same problem and I traced it to the 4.7uf cap was the prob. also the traces coming from the + side are so thin that it lifted with the desoldering. Had to run a jumper wire but works like a charm.
    I wish I found your site before – would have saved my the leg work :)
    Just giving you some feedback on the same fix. Awesome site btw.

  57. cliff sagt:

    where is the motherboard of o1w available

  58. Harold sagt:

    Hi Hajo,
    Thanks so much for posting this information. My 01/W stopped producing sound over a year ago and I have been looking for a repair source without success. I opened the back cover on my 01/W last night and the leaking C95 and C96 capicators were unbelievably obvious. The initial visual inspection shows the leakage may have damaged the R-142 and R143 resistors.

    Do you have any recommendations on where I can find/purchase the new capacitors and resistors? I have not been able to find them in my 35757 zip code and my online searches have not produced any results.

    Thank you in advance for any info you may provide and thank you again for the initial posting of information on this subject.

    Best Regards,


    • Hajo sagt:

      Hi Harold,

      thank you for sharing your experiences. Unfortunately I am not familiar with zip codes and distributors around your location in the U.S. Please see some of the other comments on this post to get a few hints on where to get the required parts. They are mostly standard and should be available at stores like RadioShack, Mouser, Digikey or others.

      Good luck and all the best,

      • Harold sagt:

        Thanks again Hajo,

        I was able to locate the capacitors at all the sources you suggested.

        Best regards,


  59. dannmarr sagt:

    What is the rating for IC53?
    Someone told me it was -5v
    I replaced it but it keeps overheating on that regulator.
    Should it be rated higher?

    • Hajo sagt:

      Hi Dannmarr,

      the rating is 5V/100mA. It may not be rated higher and it should not overheat. If it does, this indicates that there is a bad part in the circuitry behind the regulator, most probably a bad capacitor.

      All the best,

    • dannmarr sagt:

      I was using a -5 volt/100mA and I hooked it up wrong anyway. Looking at it with the flat part down and the pins facing you, I thought it was IN-Ground-Out (left to right). But the ones I purchased is Out-In-Ground (left to right). I thought all regulators and transistors had the same configuration. I guess not. Does this sound right?

    • dannmarr sagt:

      I did some research on the configurations of voltage regulators. It seems that positive and negative regulators are connected differently. That would explain alot. I’ll keep you updated and thanks for this site!

    • Hajo sagt:

      Hi Dannmarr,

      you figured it out right. Thank you for the updates.

      All the best,

    • Dannmarr sagt:

      I finally got the information correct. For anyone replacing the Capacitors IC52 and IC53, remember: IC52 is a -5V and IC53 is a +5V and they are configured differently. IC52 (left to right) is Ground, In, Out. IC53 (left to right) is Out, Ground, In. If you are using different regulators, make sure you connect them correctly! Thanks again Hajo!

  60. Ken sagt:

    I have a Korg X3 with no sound. Also found leaky capacitors near the DA converter IC18 c45 etc. Could this be the problem?

    • Hajo sagt:

      Hi Ken,

      at least this could be part of the problem, yes. The best bet would be to replace the bad capacitors and then check the fused resistors.

      All the best,