Opened it up and found R662 , 4R7 burned open. Replacement did the
same, but strangely it did so from switch on - the record circuit was
not energized. Not sure how significant this is - presumably this
means there may be a problem with the 12v coming from the BA7755
(pin1) into choke L652? Would I be right in suspecting the amplifiier
transistor Q654 (2sc3203)
here are some scans of the circuit.
this one is a close up of the oscillator stage, http://www.mediafire.com/?5qmy6qj6y060p2w
this one is the general area, with visible lines to heads and supplies
http://www.mediafire.com/?6na5n8dhgroee4c
...any thoughts appreciated.
B.
Pin one of the BA7755 is the Vcc of that chip and is supplied 12.9v via
the choke as is T652. Look for a way for that voltage to get back through
Q654 and R662 to erase ground to provide enough current flow to destroy
the resistor.
--
Live Fast, Die Young and Leave a Pretty Corpse