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Re: korg poly-61 not responding to pushbuttons

PostPosted: Mon Jul 02, 2018 8:43 pm
by orys
Which components are damaged.
I fixed it already.
Not sure if it's fixed but i found a broken trace and fixed it so it now plays but need to test further.
Will try to load the default presets and see how it goes.

Re: korg poly-61 not responding to pushbuttons

PostPosted: Mon Jul 02, 2018 9:21 pm
by Mooger5
Well yeah, "lots" is my way of putting everything in the same basket. IC10, 11 and 12 appear quite corroded.
There is definitely a good number of damaged traces around the battery.

Re: korg poly-61 not responding to pushbuttons

PostPosted: Mon Jul 02, 2018 9:59 pm
by orys
I've loaded all the factory presets and it seems that all functions work so far.
Need to sort the keybed as there are keys missing and some keys don't work.
I'll report soon with new findings but it seems to be working fine.
The ICs that look like that is because i used some type of acid to clean the corrosion and i washed the board twice in a dishwasher to clean it up perfectly.

Re: korg poly-61 not responding to pushbuttons

PostPosted: Tue Jul 03, 2018 8:13 am
by crafter57
Ok, so both MCU's have a notch(indent) on the left side of the chip and pin1 starts on the bottom row left, so count 4 pins from the bottom left and check continuity on both MCUs from pin4 to pin4. I do see some traces that could possible be a problem, but lets get thru the initial problem of Hanging on PS-61.

Re: korg poly-61 not responding to pushbuttons

PostPosted: Tue Jul 03, 2018 8:28 am
by orys
crafter57 wrote:Ok, so both MCU's have a notch(indent) on the left side of the chip and pin1 starts on the bottom row left, so count 4 pins from the bottom left and check continuity on both MCUs from pin4 to pin4. I do see some traces that could possible be a problem, but lets get thru the initial problem of Hanging on PS-61.


I traced a broken line and i fixed it.
It works fine now but some of the keys are missing and some are not working.
I am cleaning them right as we speak.
I already fixed a PolySix so i'm pretty sure i'll sort the keys too.
Just need to find some and the rubbers that go underneath as some are torn apart.
It seems to be in tune too.

Re: korg poly-61 not responding to pushbuttons

PostPosted: Wed Jul 04, 2018 7:10 pm
by crafter57
Good that you found the broken trace, that's the usual problem when the battery leaks. Hope you find a solution for the contact strips, btw, don't get those carbon discs and glue them as I've not had success with those. try to find replacement rubber contact strips instead. good luck

Re: korg poly-61 not responding to pushbuttons

PostPosted: Wed Jul 04, 2018 7:51 pm
by orys
I'm sticking plastic pieces on the actual keys to make them press lower.
The prices they charge for contact strips are ridiculous.

Re: korg poly-61 not responding to pushbuttons

PostPosted: Thu Jul 05, 2018 4:01 am
by crafter57
I'm not sure you would get a good contact if the conductive coating has worn off, guess you'll have to try it.

Re: korg poly-61 not responding to pushbuttons

PostPosted: Thu Jul 05, 2018 5:22 am
by orys
They work but i have to press hard on some of them.