Some of the brown looking crud looks like you might have had a battery or two in the battery compartment go stale and drop its gooeey guts in your Poly 800. Does the battery compartment have signs of battery acid leakage?
Mike
--- In korgpolyex@yahoogroups.com, "mcdonaldtavish" <tavishmcronald@...> wrote:
>
> Here are pictures of parts of the inside I thought looked rough/curious. This board definitely isn't in the best of shape. I would like to clean it up nice and have it looking good again.
>
> http://groups.yahoo.com/group/korgpolyex/photos/album/1019666648/pic/list
>
> List of things noticed:
> 1.Q1 missing, looks hard to find, anyone know of a replacement for this transistor?
> 2. A couple of resistors soldered in very.. not well
> 3.c88 missing?
> 2.LED soldered in for some reason?
> 3. capacitors soldered to resistors
> 4. capacitors with weird residue on them
> 5. pcb with residue
> 6. residue on side of case
>
> It looks like these pcbs are pretty dirty and need some cleaning, Would isopropyl alc be a good way to clean this? Also seems like some solder joints and pots are rusty looking and could use some deoxit? I want to make sure I don't make any big mistakes when attempting to clean this board up, any suggestions would be greatly appreciated.
>
> --- In korgpolyex@yahoogroups.com, "Peter van Beerendonk" <peter.van.beerendonk@> wrote:
> >
> > I had some problems like this also.
> > Batterij terminals where corroded but seemed to be working.
> > When I removed the batteries and used an adapter (9V 1.5A) everything was fine.
> > Worth a try, isn't it?
> >
> > On another one, a faulty cr2032 conversion on a version 7 or 8 motherboard gave similar problems (not quite as extensive as your problems though).
> > So, check the cr2032 battery (if present) or look for a CR2032 conversion.
> >
>