Have you checked that the mechanism belts are OK? This will happen if the drive belt has failed.

Thanks for the tip - you were spot on (and the eBay seller was a liar - this clearly did not work when sold!).  The two drive belts are in place (but a bit loose), but the smallest belt, which I believe is how it detects the presence of a cassette, was totally degraded - it was practically liquid when touched.  That would explain why it behaves as if no cassette is in place even when one is.  I can get a full set of the 3 belts for £15 so will buy and replace; thanks very much for your help. Searched YouTube and found video "Bang & Olufsen Beocord 2000 Cassette Deck - Repair, Mods, Belts & Service", and that proved invaluable. The eBay seller agreed to refund half the cost, so that's something.

The smallest belt is for detecting that the take-up spool rotates. This is for detecting end-of-tape and turning off the transport when the tape ends. The belt usually drives a rotating magnet and a hall-element (that detects the magnetism). So if this belt is no more, the deck always thinks that the tape has ended.

Thanks - that does explain the behaviour exactly.  eBay seller gave me a partial refund and I have ordered replacement belt kit, so hopefully, will all soon be in order.

Update - belts arrived, fitted quite easily (using the YouTube video I mention in previous post), would you beleive the damned thing works perfectly.  Needs some cleaning but honestly, sounds pretty decent.  Thanks for your help Ninni.

Hi everyone - I know this is resurrecting an old topic, but does anyone know where I could get a replacement motor for a Beocord 2000?

Update: Found a new motor at Danish Sound Parts - www.dksoundparts.com