Has my air compressor died?

[Jonathan]

It looks like I just exceeded the duty cycle rating on my air compressor whilst running the router, since it overheated and the thermal cut-out activated. My fault for forgetting about that I suppose. Now it has cooled down I reset it and the motor wont start, the lights just dim and it buzzes. I've taken the cover off and I can spin the motor/compressor by hand but it's quite hard but does go all the way round.

The compressor is coupled to the motor shaft directly, so I can't tell if the problem is with the compressor or motor without further disassembly. It's the same as this one, just significantly older:

Airmaster Tiger Turbo 8/25 Air Compressor with air hose - Take a L@@K !! | eBay

Looks like this is not an uncommon air compressor problem

Any ideas much appreciated - can't run the CNC router efficiently without it.