[reel-to-reel-man]

I don’t play much with cassette decks, but I noticed there was a PCB inside the motor itself, on the JVC's and others I worked on, a non-electrolytic cap inside the motor was the issue, may be the same on the 122, I have 4-5 of these sitting in my loft, haven’t tried to repair them yet but giving experience on others, may be an idea to pop the cover off the motor itself.

the 122 machines I have seen have motor issues, and you may have noticed, TASCAM do not list any details in the motor board, if you replaced all caps on the PCB, start by popping the cover off the motor itself and checking inside it.