[ARSCLIST] "slippery" audio cassette

["peter@xxxxxxxxxxxxx" <lists@xxxxxxxxxxxxx>]

I have a standard audio cassette that is giving me nightmares and I was
wondering if anyone has any suggestions.

The cassette has a plain black shell without any markings but the cassette
is pretty banged up and the label may have been removed.

My problem is that the cassette simply won't play.  We have tried replacing
the shell, wiping/scrubbing both sides of the tape-head-to-tail,
re-tensioning, desiccating it and tried it on 5 different machines from a
Dragon to a Dennon.  The problem we are having is that the capstan won't
engage the tape.  We have disassembled a machine and marked the capstan to
make sure it is moving.  The hubs are not binding, the tape has free play in
the cassette, it fast-forwards and rewinds just fine but in play: the
capstan spins and the tape just sits there.

It almost seems like someone coated the backcoat with silicon or some other
lubricant but, if so, it is not visibly or otherwise obvious.

Anyone encounter this problem before and have any suggestions. 

Peter Brothers
SPECS BROS., LLC
973-777-5055
peter@xxxxxxxxxxxxx

Tape restoration and disaster recovery since 1983