[Norman Raeburn]

Hi Folks, I have finally managed to get to the bottom of this. Two faults? There was an incorrect value capacitor on the disc adaptor board and I would say it's never been touched so must have been there all the time although I think it was on the ceramic input. The other fault I found after using a signal generator and scope was the levels after the disc preamp board were approx. the same but at the volume control top end there was a huge difference in signal level. This left the switching and the tape adapter board, the signal level going into the tape adapter were approx. the same but coming out were drastically different. So the second fault is on the tape adapter board, why this only showed on disc I have no idea. Perhaps the lower levels involved made a difference.
Now I found a broken piece of track on one of the transistor collectors so I assume it was bleed through that was making it work.

I would like to say thanks to all for there input and keeping me on the trail. I was beginning to loose sight of what I was doing.

Very many thanks again for the help it is much appreciated. Norman