If you simply load a tape and push "close", the tape will be extracted, the drum will spin, the pinch roller will engage the capstan, the capstan will rotate forth AND back (~1 second) and the ABS time will be readen (then everything stops for standby).
So your capstan may have a problem. May be it is just stuck (but you need to "open" the transport to rotate it from the inside), or there is a power/logic problem.
Another test to run: remove the pinchroller (be careful of the tiny white washer that holds it) and try to play/rewind/fast forward (just to check the spool motor).