I put in a cheapo hedgehog and the fan ran at full chat even with the key out. I’ve replaced it with a proper one and now it doesn’t run - just makes a groaning noise every now and then.
When I had the hedgehog out I was able to move the fan blades with a stick so it’s not jammed. I connected the hedgehog but not in its hole and the fan ran ok but a bit noisy.
I put the thing back in it’s hole and now it doesn’t run..