Discussion about the Korg PolySix synthesizer

Greetings All...

I've been lurking for several weeks now, ever since I finally had the 
spare cash to purchase a PolySix.  I've been wanting one for quite a 
while.  I used to have a Poly 61 so I'm somewhat familiar with the 
guts these things having kept that keyboard assembly working for 15 
years and replaced the leaking battery.  

So I bought a PolySix off Ebay and as it was described I was 
expecting a battery leak to be the main cause of the problems 
(described as "I don't know how this works and while it creates 
sounds some keys don't work and I think it has other problems"). I 
did, however, get it for $125 shipped. The outward cosmetics are very 
good, the only blemishes are worn "wood" corners at the bottom rear.  
The first thing I did this evening before I plugged it in and turned 
it on was to open it up and check out the battery and the general 
condition of the insides.

Not too bad *looking* in there: the battery had already been 
replaced, however it doesn't look like it was done thoughtfully: 
resistor R91 and capacitor C40 are still there; the new battery is a 
lithium battery (I know I have to get resistor R91 and capacitor C40 
out of there); and the negative side is attached to the trace that 
runs along the board's side with a thick piece of copper wire. It 
looks like a few traces may have been hit with some battery acid or 
something because they're ever-so-slightly bubbly.  All look intact.  
The most noticable thing though is that the solder on the holes 
around IC31 are corroded, although the legs of IC31 *look* fine.

Okay, so I'm going to have to clean that up.  Or should I bother and 
just buy Scott's replacement?  Here's why I ask:  I closed up the 
PolySix because I *had* to hear it.  Upon power up everything looks 
normal except that bank buttons A and B and patch buttons 1 and 2 
stay lit, although slightly dimmer than the brightness of the other 
LEDs on the other buttons (when turned on, of course).  It seems as 
though I can select those patches and banks, but the LEDs on those 
buttons never go off.

Secondly, I can't really hear a difference when I select the 
different waveforms, and the octave doesn't change.  The PW and PWM 
do work, though.  Everything else seems to work fine.  I checked the 
voice chips by watching the little LEDs on that board light up as I 
hit a key and they all work.  The keyboard needs a cleaning, but it's 
not as bad as my old Poly 61 used to get.

Would these problems be resolved after a good cleaning of the buttons 
and pots and obviously fixing the crappy battery replacement job?  Or 
are these issues more ominous and it would be less hassle to get 
Scott's board?

Whew!  That's a lot of typing.  Thanks for reading and thanks in 
advance for your advice!