[davyrocket2]

Peter head drum hall effect I.C, devices are only found on direct drive motors ,the signal that you should be looking for is ,flip flop pulses sent from the north south of the drum flywheels magnets a very common fault on these machines is pulse failure due to the flywheel slipping on the shaft a gap approx of the thickness of your fingernail is all thats required .I think the fault on your machine will be sorted out in the correct setting up adjustment of the drum servo circuit as regard the other fault get clear and normal playback of 625 lines before altering for playing 405 line recordings regards David