USB drives: if it's a flash drive, Stilly, you may be right about it being borked. Flash drives have a longer mean time to first failure than spinning rust, but said first failure is more often fatal. That's the trouble with relying on things which are reliable .... once you do, they aren't.

Treat it as read-only, and you may be able to recover things it hasn't eaten. Apologies if I've got this round my neck as usual. I've got a size 16 in mouths.