[Uncle Bulgaria]

Thanks Lawrence! I'll work through that once I've done today's work. It's just a CR 240, not an AV so your diagram will be correct. SDS sent me one for the right serial number so it included the Hall-effect switch rather than the photo-diode assembly on the PDF I found online.

I can make a better scan of the diagram when I get a moment later today and post a link, if that's helpful.

I was up most of the night trying to track down the bizarre fault that has now reared its head - thinking all was well I tried recording some test tones. The fluttering warble is extreme on a tape I record, and on tapes I've previously recorded on this very machine that a couple of months ago were impressing me with their high quality. However, when playing a commercial tape extended notes are not at all warbly. I'm going to do a recording on the only other cassette deck in the house and play it back on the Uher to see if that narrows it down.

I've checked the motor electronics at MP2 which are of an even amplitude and frequency with only a slight wavering up and down as if carried on a lower frequency sine wave. The tape path has been cleaned. The only change since picking it up again after a few months' hiatus has been changing that capacitor...