Technics Cassette Deck Repairs
The mechanism wouldn't do anything, the large square belt that drives the gear assembly for the functions (old mode switch) was stretched, a new one from CPC cured it (2mm by 51mm).
This late 1970's cassette deck was running the tape at high speed, it was either the capstan motor lost its speed regulation or the take-up reel pulling the tape, it was the latter. The spring had come off the pinch wheel, refitting, cured it, after a struggle keeping the spring in position while slipping the wheel over the pivot!
No sound was cured by re soldering the large IC at the front RHS of the main PCB.
Dolby switch had bad contacts, switch cleaner and service. Okay now.