MS-20 problems

[AvS]

Thats a bummer man. :(

Your pulse Width-knob is working corretly though. The width of the pulse get so narrow that the waveform simply dissapears past 3'o'o clock - perfectly normal on an MS-20.

I have experienced the same problem with the lfo bleed on another synth. Was two dried out capacitors in the psu that was really easy to fix. Might not be the same issue here but perhaps it is.

Tough question if you should fix it with the help of your friend or send it back. It's proberbly an easy fix but they did rip you off and this kind of behaviour should have consequences. Maybe tell them whats wrong and ask them to cover the repair? Perhaps a long shot but If you send it back they will most likely just rip someone else off.

[Xero]

The faulty envelope is likely caused by a dead 4069 CMOS IC in the EG circuit. That same IC is used in a few places in the ms-20 and often dies. On mine, there's one that's part of the ESP circuit that died, causing my ESP not to function correctly.

4xxx series cmos IC's are often dead or dying, modern ones are made to much better standards, some would say, replace them all...but that might be overkill.

I'd probably look for any CMOS ic's as part of the other circuits that you're having issues with, more than likely that's the cause, or, perhaps your knobs just need cleaning.

If you do decide to keep it, at the very least, get a partial refund from the seller.

[Bergman]

Ok, didn't know about the pulse width knob. Now that I do, it makes sense.

The seller was sorry and told that they allways check the gear prior to sending it out, but this time something else has happened. He also told me to get it fixed here in Finland and they will cover the costs, but I should get a quote first.

Things are starting to look better, now I just need to know where to get this repaired.

[Bergman]

Originally Posted by Xero

4xxx series cmos IC's are often dead or dying, modern ones are made to much better standards, some would say, replace them all...but that might be overkill.

Yeah, there are 18 * 4XXX series IC's and 5 * 14XXX series IC's, pretty much every IC should be replaced then.

Originally Posted by Xero

I'd probably look for any CMOS ic's as part of the other circuits that you're having issues with, more than likely that's the cause, or, perhaps your knobs just need cleaning.

I was also thinking about spraying the knobs, but I didn't want to open the MS and I also think that the problem lies a bit deeper - like in the IC's or caps.

Now I just have to find a technician to fix mah baby.

[jasonM]

Originally Posted by Bergman

I just received Korg MS-20 that I recently bought. I got this through eBay auction and the original auction said things like:"ALL BUTTONS KEYS FULLY WORKING." and "HAS BEEN CHECKED AND SERVICED BY OUR AUDIO SERVICE DEPARTMENT", except they aren't and I quess it wasn't (under the keybed there was a huge pile of "dust dogs" and rusty screws here and there).

Everything went smoothly with the courier service, the box was intact and the synth was properly packed. So I quess the shipping is not the thing to blame here.

The problems are:
1. Faulty Envelope Generator 2: Sustain is constantly on and Hold-knob does nothing.
2. Modulation Generator leaks to Frequency Modulation, causing constant modulation to oscillators.
3. Pulse Width-knob is not fully working. It stops modifying the signal at 3'o'clock

And here is a quick video I made to illustrate the problems:



Question is, should I send this back (they offered return 7 days after delivery) or should I find someone here in Finland to repair this or try to do it myself (if it's couple of broken IC, I can change them myself/with help of my friend who is a real soldering wizard)?

Thanks guys and gals!

Hi Bergman, did you get to fix your ms20 or did you return it?
i also just bought one which fits your exact description ( Dirty) and it has the VERY SAME problems!..... whats even more worrying , the seller had the same words in the description : "VINTAGE SYNTH KORG MS20, USED IN PRO STUDIO FOR SEVERAL PROJECTS. ALL BUTTONS KEYS FULLY WORKING. EU POWER PLUG. HAS BEEN CHECKED AND SERVICED BY OUR AUDIO SERVICE DEPARTMENT" .

Was the seller from Holland by any chance?
anyway, it does come with a 3 months warranty and the seller excepts returns . so i might return it if fixing it is going to be an epic of a story.

Please let me know weather you returned it and i bought it

[NYMo]

Name and shame !

[draven5]

There's another thread talking about how bad ebay sellers are. I have been scammed by many with many of my synths. Send it back get your money back. Keep detailed pics and vids of the problems in case they won't refund. File a claim with ebay.

[jasonM]

Originally Posted by NYMo

Name and shame !

I am hoping that it wont come to it and that it is just a coincidence ( though that voice in my head is telling otherwise) .

I contacted the seller to point out the faults .... i will wait to see what he has to say . i thought about returning it but i really don't want to risk " i have not received the item" and lose out twice. so a partial refund is what i want... i think

I might just get it fixed will update you.

[jasonM]

Originally Posted by draven5

There's another thread talking about how bad ebay sellers are. I have been scammed by many with many of my synths. Send it back get your money back. Keep detailed pics and vids of the problems in case they won't refund. File a claim with ebay.

Thank you for the advice.
The only thing is , what if i return it , and he claims he never got it or that its not his signature on the "received" papers?. i understand that Ebay has the buyers protection etc as well as the seller accepting returns but... i dont want to endure a long winded process coupled with the risk of losing the machine it self .

Thanks again and i will post updates.

[Bergman]

I never sent it back. I got it fixed by a pro here and it only took about 2 months (finding the pro, because there aren't many here in Finland, delivering the synth to him, waiting for the repairs and getting it back).

The problem was two broken potentiometers. The one that controls EG2 "hold time", causing the infinite hold and "frequency modulations" MG/T.EXT potentiometer that caused constant modulation to oscillators. Also the power cords was changed for IEC-plug (C14).

These repairs costed 90€ and was refunded back to me by the seller. And yes, he is from Holland.

Hope you get yours fixed, MS-20 is a bitchin' synth!

[jasonM]

Originally Posted by Bergman

I never sent it back. I got it fixed by a pro here and it only took about 2 months (finding the pro, because there aren't many here in Finland, delivering the synth to him, waiting for the repairs and getting it back).

The problem was two broken potentiometers. The one that controls EG2 "hold time", causing the infinite hold and "frequency modulations" MG/T.EXT potentiometer that caused constant modulation to oscillators. Also the power cords was changed for IEC-plug (C14).

These repairs costed 90€ and was refunded back to me by the seller. And yes, he is from Holland.

Hope you get yours fixed, MS-20 is a bitchin' synth!

Thank you so much for getting back to me. ok then , so its not the same ms 20 , though both have the exact same problems , and , same seller .

So far , he is still sticking to the company line of "all checked all serviced..." and has asked what do i want to do ... i want him to pay for the repairs , im just waiting for a quote . if he gives me any headache , i might even fly out there and ask for a replacement of a refund

Thanks once again
( and yes they are amazing )

[jasonM]

Update:
The e-bay seller has paid for the repairs cost. i found a brilliant repair team in Suffolk and got the MS20 Back in working order , they cleaned it and even changed the EU Power plug to a Uk plug .

Although the seller paid for repairs, i would never buy from him again because how he described the ms20 was misleading. Just amazed at how he has such good Ratings.

it's a shame.... he did have some amazing vintage s
Thanks again for all who helped out with advice.