Teac Cassette Deck Repairs
This had noise through the left channel. It was narrowed down to the Dolby board even with Dolby switched out. The input signal goes through the Dolby section (I didn't have the service manual). Turned out to be a 2SA763 there are lots of them!
This was not working because the pinch wheel pivot had seized up, removed it with a gear puller after a struggle, re-profiled the pinch wheel and gave it a service, made excellent recordings after - nice deck.
Another 3340S for repair. It needed the safety micro switches fitting that are operated by the RH tension arm as they were missing! The heads also required realigning.