Yamaha CS80

Hi chaps,

I have found another CS80 close by me and it's up for grabs - but I am
slightly concerned. It all seems to be working apart from a couple of
voices. 

(On my current CS80 which works 100%- when I bought it back in 1986 a
voice didn't sound and it turned out that someone had tweaked the
wrong preset - (VCA?) - and it just wanted setting up again..) 

So this new find might well be similar.... but otherwise I am
concerned that it has live a great part of it's life stored in a damp
garage and the metalwork inside has this white powder on it. It won't
come off really and some of the brass screw bolts are dis-coloured
with it etc... My main concern is how this has affected the solder and
PCB's. Anyone here have any similar experiences and actually how bad
does it have to be visually before it's an issue?

Like I said, the synth seems to work OK except for a couple of voices
and it's in need of a tune up.

Obviously I need to base my offer on info collected from sources such
as our group here.

Many thanks in advance.
TOM