I have 3 of this big boomboxes but all have the same problem with the potis:
Mic fader- Tape fader- bass- treble works just on one channel.
I opened this boxes, but what i found in one box is a blown up capacitor on the potiboard.
10 Volts 100 µ... I measured 13 volts.
Pleas pleas help me... i dont know what to do...
I paid a lot of money to have *just one* fully working original 777, not 3 broken scrap boxes...