I think you have more problems than simply cleaning those PCB's up.
Q1 is a tr2sb731 PNP transistor. You should be able to find a suitable replacement.
How are you powering up the unit? Batteries? I don't see how you can power it with a 9v plug in supply with Q1 missing.
Someone's been in your unit and apparently butchered up the components.. adding components here and removing them there...
I'm surprised it does anything at all from the looks of your pics.
Maybe someone started to attempt fixing it and gave up on it?
IMO, it's going to need a lot of time spent tracing down what was modified and return it back to OEM spec. Have you found the schematics/Service Manual for it here in the Files section?
I find that using acetone to clean up boards works good.. especially to remove excess flux residue.
-Blaine
--- 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.
> >
>