Assuming you have tried it with multiple tapes, I would contact the seller as its obviously not in “superb condition”.

The drive stops because no tape motion is sensed. - Bad belts - Bad motor - Lack of power to the motor (bad fuse) - Seized take-up reel - Cracked solder joints at the connector to the drive - Broken off lead for the motion sensor - Any combination of the above. If it happened after shipping, I would check if the motor is running when the deck is out of standby. If it doesn't check the fuse on the regulator board - and its holders. But I agree, the seller should help you with this or take it back. Martin

Hi Mark,   I contacted the seller as soon as the problem manifested itself. There will be no problem about sending it back and getting a refund. But it would be good to get to the bottom of it.

Hi Dillen, Thanks for your comments. The description on the listing was "superb condition, belts replaced, works flawlessly", or words to that effect. The capstan is turning okay. The tape advances briefly then stops; similarly with fast forward and rewind. It strikes me that something is kicking in the auto-stop mode but I can't work out what. Cheers