I've done what I can on this unit. Recapped the motherboard and trying to sort out the cassette unit. That has included using a donor mechanism from another machine, changing the belts for the best I could find (couldn't find exact match) and the tapes play, but around every track, there's a dip in volume for a few seconds before it comes back. I'm not sure whether it just needs exercise or whether I'm looking at something more serious that is now beyond my limited tinkering repairing. Grateful for people's thoughts on this please.