m1 no sound fix

Hajo's… somewhat really new something« TorwarnleuchteLautsprecherschalter »

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).

of 27Hajo's » Blog Archive » Korg 01/W “no sound” repair

10/28/2011http://hajo.kessener.net/electronics/korg-01w-no-sound-repair/

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.”

This entry was posted on Sunday, August 3rd, 2008 at 2:30 pm and is filed under Electronics, Music & Gear. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.

103 Responses to “Korg 01/W “no sound” repair”

Peter says: September 2, 2008 at 7:54 pm

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, Peter

Reply

1.

Anonymous says: September 23, 2008 at 12:51 am

Excellent work & a really effective help to everyone…!

Reply

2.

Sam says: September 25, 2008 at 5:29 am

3.



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

Reply Sam says: September 25, 2008 at 5:48 am

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!!!

Reply

◦

j-man says: October 5, 2008 at 2:06 am

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

Reply

4.

j-man says: October 5, 2008 at 1:42 pm

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.

Reply Hajo says: October 5, 2008 at 2:19 pm

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).

Regards, Hajo

Reply

5.

j-man says: October 5, 2008 at 3:40 pm

Found the manual, thanks to Yahoo’s 01W user group (http://launch.groups.yahoo.com/group/korg01w-list) C102 and C103 value is 0.1 microfarad. Of course… I should have guessed it Hajo, I’ll send infos and pictures as soon as possible. Thanks again for your unvaluable work, and also to Sam for his great contribution.

Reply

◦

Frank says: November 4, 2008 at 4:11 am

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.

Reply

6.

Sam says: November 9, 2008 at 11:15 pm

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.

Reply Sam says: November 10, 2008 at 12:00 am

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

Reply

◦

Frank says: November 14, 2008 at 1:53 am

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.

Reply

◦

freshman says: November 18, 2008 at 9:54 pm

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

7.



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.

Reply Hajo’s » Blog Archive » Freshman’s 01/W refurb says: December 10, 2008 at 11:06 pm

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

Reply

◦

andy says: November 19, 2008 at 4:49 pm

hey frank, you said “something broke inside that usually happens when you don’t use the keyboard for

8.



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.

-a

Reply Frank says: November 21, 2008 at 11:27 pm

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!

Reply

◦

TJ says: December 9, 2008 at 9:48 pm

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?

Reply

9.

Hajo says: December 10, 2008 at 11:15 pm

Hi TJ,

neither special order nor expensive. See this comment for an explanation and maybe also this article for a few shots. Hope this helps.

Regards, Hajo

Reply

◦

S.D. says: December 31, 2008 at 11:31 am

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.

10.



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

Reply Hajo says: December 31, 2008 at 2:35 pm

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.

Regards, Hajo

Reply

◦

S.D. says: January 21, 2009 at 9:19 am

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: http://pics.studiorepair.de/Korg/01RW/EL_Foil/slides/Korg_01RW_LCD_Blown_Ca

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.

Reply

■

Hajo says: January 25, 2009 at 1:57 pm

S.D.,

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.

Regards, Hajo

Reply Donal says: April 8, 2009 at 2:29 pm

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.

D.

Reply

11.

Donal says: April 10, 2009 at 7:19 pm

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!

D.

Reply

◦

Hajo says: April 12, 2009 at 11:08 am

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.

Regards, Hajo

Reply

◦

Donal says: April 12, 2009 at 11:38 am

Hi Hajo,

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

◦



Reagrds,

Donal.

Reply Hajo says: April 12, 2009 at 4:16 pm

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.

Regards, Hajo

Reply

◦

Donal says: April 13, 2009 at 2:55 pm

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!

Donal.

Reply

◦

Hajo says: April 13, 2009 at 7:49 pm

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.

Regards, Hajo

Reply

◦

Donal says: April 14, 2009 at 1:36 am

◦



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.

Regards,

Donal

Reply Donal says: April 18, 2009 at 9:58 am

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!

D.

Reply

◦

Simon says: April 22, 2009 at 9:36 am

Donal

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…

Thanks

Simon

Reply

◦

Donal says: May 2, 2009 at 2:09 am

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.

Regards,

◦



Donal.

Reply Simon says: May 4, 2009 at 7:45 am

Thanks Donal!

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

Thanks

Simon

Reply

◦

Donal says: May 14, 2009 at 10:24 am

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.

D.

Reply

◦

Hajo says: May 21, 2009 at 3:48 pm

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.

Regards, Hajo

Reply

◦

samuel says: April 25, 2009 at 4:33 pm

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

Reply

12.

Hajo says: May 1, 2009 at 10:47 am

Samuel,

◦



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.

Regards, Hajo

Reply James Knight says: May 26, 2009 at 7:02 am

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.

Reply

13.

Hajo says: May 31, 2009 at 11:48 am

Hi James,

see this answer. For a replacement EL-foil, I’d recommend MIDI-Rakete, they ship worldwide.

Regards, Hajo

Reply

◦

Damien Coutrot says: May 26, 2009 at 1:07 pm

Hi, 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 ?

Regards. Damien

Reply

14.

Trung says: May 28, 2009 at 6:03 pm

Hello, 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

15.



Reply Hajo says: May 31, 2009 at 11:44 am

Hi Trung,

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

Regards, Hajo

Reply

◦

BigBillKahuna says: August 5, 2009 at 3:42 am

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?

Reply

16.

BigBillKahuna says: August 5, 2009 at 3:53 pm

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.

Reply

◦

Hajo says: August 16, 2009 at 4:46 pm

Hi BigBillKahuna,

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

Regards, Hajo

Reply

■

Jim Owens says: September 14, 2009 at 2:16 am

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

17.



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.

Reply Jim Owens says: September 14, 2009 at 2:54 am

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?

Reply

◦

Hajo says: September 16, 2009 at 5:14 pm

Hi Jim,

a cleaning is recommended and worth a try, in my opinion.

Regards, Hajo

Reply

■


Hi Jim,

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

Regards, Hajo

Reply

◦

Jim Owens says: September 20, 2009 at 6:48 am

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

18.



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!

Reply Tim says: September 24, 2009 at 9:46 am

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.

Reply

19.

Aykman says: November 29, 2009 at 10:50 pm

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……….!

Reply

20.

Hajo says: December 1, 2009 at 11:20 am

Hi Aykman,

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

Regards, Hajo

Reply

◦

kyzee says: December 5, 2009 at 6:16 pm

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.

Reply

21.


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.

◦



Regards, Hajo

Reply Sparky Montoya says: December 5, 2009 at 6:30 pm

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.

Thanks,

Sparky

Reply

22.


Hi Sparky,

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

All the best, Hajo

Reply

◦

Aykman says: December 17, 2009 at 11:30 pm

Hi,

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

cheers

Aykman

Reply

23.

Peter says: December 31, 2009 at 1:34 am

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

24.



Reply Hajo says: January 4, 2010 at 11:44 am

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.

Regards, Hajo

Reply

◦

Angel Sing says: January 31, 2010 at 5:46 pm

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.

Reply

25.

Hajo says: January 31, 2010 at 5:51 pm

Hi Angel Sing,

try these links on how to initialize the 01/W and use the “preload” function:

http://www.sweetwater.com/sweetcare/ts/detail.php?Index=16001 http://indra.com/~cliffcan/01faq.htm

Regards, Hajo

Reply

◦

Paul says: February 19, 2010 at 9:18 pm

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! ..paul

Reply

26.

Hajo says: February 19, 2010 at 9:25 pm

Hi Paul,

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

◦



Regards, Hajo

Reply Paul says: February 19, 2010 at 9:36 pm

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! ..paul

Reply

◦

Hajo says: February 19, 2010 at 9:50 pm

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.

Regards, Hajo

Reply

■

Paul says: February 19, 2010 at 10:11 pm

great! thanx a lot!

Reply

■

Fran says: March 9, 2010 at 6:58 am

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?

Reply

27.

Hajo says: March 13, 2010 at 8:05 pm

Hi Fran, is it the EL-foil or the inverter that is now making noise?

Regards, Hajo

Reply

◦

Fran says: November 8, 2010 at 7:48 am

I believe so. But it’s difficult to determine exactly where it’s eliminating from.

■



Reply Gleb says: May 19, 2010 at 11:13 pm

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

Reply

28.


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.

Regards, Hajo

Reply

◦

Gleb says: May 22, 2010 at 1:26 am

Thanx Hajo,

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

one more thank you.

g.

Reply

■


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, Hajo

Reply

■

blob says: May 26, 2010 at 12:53 pm

29.



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 :-/

Reply Hajo says: June 3, 2010 at 3:55 pm

Hi Blob,

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

Regards, Hajo

Reply

◦

Gleb says: May 27, 2010 at 11:08 pm

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?

Reply

30.

Hajo says: June 3, 2010 at 4:18 pm

Hi Gleb,

send your photos to 01w [at] kessener.net.

Regards, Hajo

Reply

◦

joe says: June 4, 2010 at 9:30 pm

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.

Thanks,

Joe

Reply

31.


Hi Joe,

◦



maybe see this comment from another visitor located in the the U.S.

Regards, Hajo

Reply gabriel says: June 9, 2010 at 6:21 am

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.

Reply

32.


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.

Regards, Hajo

Reply

◦

Alan says: June 25, 2010 at 4:23 am

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

Reply

33.

Hajo says: July 12, 2010 at 7:35 pm

Alan,

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.

Regards, Hajo

Reply

◦

Jonah says: 34.



July 8, 2010 at 7:12 am

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.

Reply Hajo says: July 12, 2010 at 7:47 pm

Jonah,

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).

Regards, Hajo

Reply

◦

peter says: August 28, 2010 at 5:05 pm

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 ?

Reply

35.

Hajo says: August 29, 2010 at 3:56 pm

Hi Peter,

see http://indra.com/~cliffcan/01power.htm for reference.

Regards, Hajo

Reply

◦

peter says: September 4, 2010 at 12:54 am

Yeah, the bird is singing again. That keyboard was quiet for some years, almost threw it into the bin. Lucky, I found this webarticle. There were some really tiny bits of dirt in the electronic board, TINY.

peter

Reply

■


■



Hi Peter,

my congratulations and thumbs up, that you gave it a try!

Regards, Hajo

Reply Pieter-Jan says: September 9, 2010 at 1:16 pm

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!

Regards, Pieter-Jan (the Netherlands)

Reply

36.

Gloria says: November 1, 2010 at 12:37 am

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.

Thanks

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

Thanks Gloria Memphis, Tn

Reply

37.

vito says: July 30, 2011 at 5:49 pm

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

Reply

38.

Hajo says: July 30, 2011 at 6:02 pm

Hi Vito,

C97…C100 are 100nF ceramic capacitors.

Regards, Hajo

◦



Reply vito says: July 30, 2011 at 6:51 pm

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!!!

Reply

39.

angela says: August 23, 2011 at 9:15 pm

Hi

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 Angela

Reply

40.

Hajo says: October 24, 2011 at 7:00 pm

Hi Angela,

you did everything right. I am sorry, but do not have a clue either.

All the best, Hajo

Reply

◦

Enrique L. says: September 14, 2011 at 8:22 am

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

Reply

41.


◦



Hi Enrique,

thank you very much for your kind feedback!

All the best, Hajo

Reply Bab says: October 22, 2011 at 9:22 pm

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, thanks

Reply

42.


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, Hajo

Reply

◦

Bojan says: October 26, 2011 at 6:05 pm

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.)

http://www.flickr.com/photos/69174974@N08/6283583114/

Reply

43.

Leave a Reply

Name

Mail (will not be published)

Website



Submit Comment



m1 no sound fix

Documents