I just got a WM-F15 on e-Bay for about $30. The radio works fine. The cassette desk did not work at all, at first. Thanks to some information here and elsewhere, I was able to source a belt and replace it.
Now I find myself with a WM-F15 that can do the following:
1. Fast forward (Batt light on) 2. Rewind (Batt light on) 3. Play for a few seconds (Batt light on) after which the Play button pops and the tape stops.
The tape will continue to play if I hold the Play button down, but there is clicking every few seconds as the unit wants to stop the tape.
i would guess that the belt is to tight which can trigger the auto reverse. i have had several that will flip back and forth but not play. a looser belt might be the fix. the other thing is the mechanism that triggers the auto-stop and autoreverse can be worn out. i don't know how to repair those but some members are more knowledgable on that subject.