I just got a new 70mm case fan and it's got a problem. It won't spin when hoo ked up to my MoBo's fan power plug. It's a 3 pin and the MoBo's a 4 pin connector - no problem, the old fan was a 3 pin as well and still works (grinding bearings) so I know the positioning and MoBo are fine. The new fan has a 3 pin connection and an extension to a 2 pin molex connector. The fan works fine driven by the molex, so wtf?!?!

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