[Uncle Bulgaria]

Thank you David, that's very kind. It was a lot easier for me to trace them without the protective sleeve featured on yours - some fine tweezers, and despite the variable colours they were quite easily separated.

I hadn't realised your PDF manual included the sheets - my physical copy has the booklet as one entity, which finishes with the list of component reference numbers. That booklet has no serial number indication, but the two separate folded sheets do and they look exactly the same as your PDF.

Your two colour one must be the "AF- and Power Supply Circuit Diagrams", and would seem to be the definitive edition for both our models.

I still can't find b1 anywhere on the sheets. The relays marked in the board 600 'magnet control electronic' diagram only feature the three wires that connect to the far left and right of the physical board 600. I think as these have resistance values in, and remembering my investigations with the CR 240, they are the coil connections, rather than anything to do with the switched relay connections.

I'll try to trace the a2 and a3 tape head connections in case that sheds light on my solenoid issues. Some of the connections are wrong, as playing in reverse works, but attempting forwards causes the reverse solenoid to oscillate, and pause doesn't work either. Fast forward and rewind don't mute the output (perhaps this is normal behaviour) so are quite noisy in the headphones. This latter could be something to do with faulty decoupling capacitors, I suppose.