Korg Poly-61 Non-midi, non-working keyboard opinions

Hi there. I have a chance to pick one up for $50. The seller says and has photos of it powering up. He claims that it is an easy fix and he even has a local repair guy that know how to fix it. He claims its a common problem. Are any of you familiar with this issue? I sent an email asking if he received a quote for the repair and if it was ever working while he owned it. I also asked if he knew of any other issues. If this was the midi version I probably would have already snatched it up.

Any tips would be greatly appreciated.

Thank you

Leaking batteries and non-working keyboards are a standard issue with Polysix and Poly-61. In most cases it is dust and oxidized contacts. Even in harder cases there are spate parts available on ebay and in some forum, mostly for reasonable prices. I have seen complete mainboards with MCU and chips for about 150€.

Thanks for the info. I heard the leaking battery can eat the traces on the board. Other than that I know nothing about it…except that it sounds good.

The MonoPoly and Polysix sound better, but for 50 bucks i would buy it unseen. Even as source for spare parts a deal.

I found a battery and envelope chip replacement guide with pictures and it doesn’t look like any fixes on this board would be too tough. Maybe sourcing chips would be, but the battery job looks easy…of course if the traces are bad then that changes things a bit.


Poly 61 has some superraw poly sounds… And it’s easy to midify to… If the battery leakage isn’t really terrible go for it…

Thanks shiftr.

My title is misleading I just meant it is not working as a whole. I don’t know if the actual keys are flaky or not. He said he got a $140 quote to repair it all locally. It looks pretty clean, but the photos are dark. I am calling him after work to discuss. I already ordered the battery…haha. The battery looks like a really easy fix…definately something I could do myself.

Can anyone recommend a cleaning product for the board and traces if needed?

IPA should do it, at least in my experience… Something to dissolve any extremely stubborn leaks might be needed, but I’m out of my comfort zone on those :confused:
(I’d just give everything I’ve got a whirl… Heh… )

I did the keyboard clean a few times myself… it is something wich comes back every time. But these guys sell a nice midi kit for it.

Thanks V’cent and shiftr.

I just talked to the seller and he said it did work for him years ago. He said the battery is corroded, but his synth repair place said it was fixable. I guess the degree of damage could vary quite a bit. But for $50 its not that big of a gamble. I could probably easily fix and broken traces via jumpers, right?

Paying someone a 150+ to bring it back to life is not something I am too interested in. I am going to pick it up tomorrow after work.

yeah 200+ just to have a working poly 61… i didn’t like it when i took it from a store to try it (i tried every crap digital synth apparently)
but just the material is definitely worth more than 50€/$

Hi everyone. I picked up the Poly61. It seems to be in pretty good condition. The corrosion doesn’t seem to bad, but I am sure I have some work ahead of me. Some of the component leads look a little corroded, but nothing too extreme. The overall condition looks to be good. A few bruised corners are the only issues I can see. What do y’all think?

I’ve got one of these, was a freebie that was in pretty poor condition when I got it. I like the sounds you can get out of it and though the keyboard is pretty average, it works pretty well now. Can’t complain about a free hybrid analog/digital poly synth.

I’ve not put a new battery in mine yet, so when I turn it on I get random patches each time.

This guy has posts providing detailed reference on how this synth works and some repair info: https://plus.google.com/107231411209962227230/posts

You are aware that this sludge on the PCB is dried acid from the Battery tha will keep corroding everytime it gathers a bit of humidity???

I think the mainboard is still worth a rescue. It would be crucial to desolder the battery first and fast, then to dismount the mainboard and brush it with alcohol. This should reveal the real state of this baby. But i have seen worse, even corroded traces are repairable with a piece of tiny lead, a cutter and a little amount of clear base coat.

Yups, the board itself looks OK; so unmount, rip out the battery and try cleaning it with demineralized water and then alcohol to get off the sludge. Let dry thoroughly (40-50° in your Oven overnight…)

… and we’re heading into the cooking thread… Not so sure if it’s a good idea to put an alcohol drenched pcb board into a gas oven though. Electric ones should be OK.

It depends: IPA > 90 % vol. alc. > 54 °C = BURN BABY BURN !

Worst case you know your PCB is faulty :wink:

Yeah I am aware this needs a serious cleaning. The battery will be removed this weekend hopefully. Thanks again for all the tips