FINALLY got it sorted!
Appears that battery corrosion at some time had gotten behind one of the IC sockets.
Nothing to see when IC removed, no sign of anything on rear of board or front really.
But it was enough to screw something up.
Any way I now have a working Comet.
Funny bloody machine to listen to.
Anyone else who has one will know what I mean.
Thanks to all who helped in this and my other thread on Sys9 sound.
Cheers,
