I have a Beogram 3000 type 5228 which I've serviced with a friend of mine. Everything else seems to be working as it should now, but there's one thing we couldn't get rid of.

The turntable makes some kind of mechanical "spinning" noise, which is fairly constant and clearly audible on quiet parts of a record or when run without music. Also, the noise doesn't come of the speakers, only from the turntable itself.

The motor is quiet as a whisper, so my guess is that it's generated somewhere in the idler wheels or something. The black plastic bottom of the Beogram seems to amplify the noise considerably - if it's taken off while the motor runs and spins the plate, the sound almost completely disappears. The plane, soft or hard, on which the turntable is placed while running doesn't seem to effect the noise much at all. Also, I've tried to soften/dampen the places where the wooden body meets the black plastic bottom, but that wasn't helping much at all...

Any ideas as to where this noise is coming from and what to do with it?

Thanks a lot in advance -- the forum's been an interesting & helpful read so far!