I tried rejuvenating the pinch rollers with naphtha, but I think it may be one of the motors that is flat spotting, because it just stops randomly. Seems to be more prevalent TDK SA 90 tapes that came from the same batch as far as I remember. It plays Maxell XL II tapes all the way through, which makes me wonder is it really the motor, or is it something in the tape path?
edit: it seems after it heats up that it does this more often, and it is doing it even on Maxell tapes now. Sounds like the classic motor problem, and I’m looking to return this because it was supposed to be serviced. My technical ability is not there to fix this myself.