poly61m deathsmell fix
I’d been working on a track and moved a bunch of stuff around, including my battered Poly61M. After recording I turned everything off for the night. And mistakenly left the Korg on.
I woke up at about 3am thinking “what’s that godawful smell?”
Yeah, that looks wrong doesn’t it?
Mmmm, 30-plus years of dust. In the middle we have a bulging Rifa 33nF paper capacitor. It doesn’t smell very nice.
The synth still works, but worryingly the power switch doesn’t actually turn it off any more, so the capacitor has failed short.
I found the recommended replacement according to the Rifa datasheet – here’s the bottom of the old burned-up one on the left and the new one on the right.
…and now it works fine again: boring fix, sorry everyone.
Here are some random photos of the inside. I had to take the keyboard out to get the power supply board out, gahhh
Here’s the main voice board, socketed SSM2056 and all
And this is probably the main processor board – there’s another board wonkily attached for MIDI on the left which I cleverly didn’t get a photo of.
Yes, the 80s:
The electrolytic capacitors in the power supply could probably do with replacing – as could the tactile switches on the front panel – but that’s a job for another day.
Oh and the keyboard barely works as well, which is standard with these. I’ve been in it before to try and fix it but they always die again, it’s one of those inherently shit designs. Good thing it’s the M version and I can control it externally.
I managed to threaten a few keys into action by banging seven bells out of it – here’s me absent-mindedly stepping through some presets and CLICK-CLICK-CLICKING the half-dead buttons.