Hi all,

Many thanks for the replys, very interesting.

I've done a bit more investigation now I have the schematics. I can't
see anything obvious like blown caps or anything. However the chip the
circuit uses for driving the sled motor, drive spindle and
(importantly) the focus/tracking coils (which I think is causing the
oscillation) is an LA6525 surface mount IC. When the power is applied
and the optical head vibrates, this IC gets very hot, very quickly.
According to the datasheet for this iC it does have thermal protection.
Anyway if I disconnect the optical assembly ribbon cable, the chip does
not get hot.

I have ordered a KSS-240A so I can try it when it arrives. Does anyone
think it's worth getting hold of the chip as well (assuming I can)

Cheers

Steve