Why wont my PS4 fan work?

So no dramatic event happened that I am aware of but the fan in my PS4 stopped working. I cleaned it a couple months prior and then one day, the machine was completely silent when running (very odd for a launch day ps4 that normally has a pretty noisy fan)and would over heat almost immediately upon starting any game. Per the advice of a lot of forums I ordered a new fan and thermal paste. Replaced them both, put it back together and still the fan wont spin at all.