PC not displaying anything

[AugOwnz]

A second PC I just built from parts that I had laying around was working until yesterday. I left it on downloading stuff from steam during the night and now it doesn't display anything. Tried removing the GPU (gtx 570 just momentarily) and using the integrated gpu but no luck. Cpu fan, gpu fan and hdd power on but the only case fan I have doesn't (tried other fan ports, still doesn't spin). Clearing cmos doesn't do anything and switching to the second bios chip doesn't do a thing aswell. Removing the motherboard battery doesn't seem to do anything either. Even unplugging it and holding the power button for a minute doesn't. Tried the ram in all slots in dual or single channel with a single stick so that's probably not it. All points to me to the motherboard being dead, but any other pointers?

Specs:

Intel core i5 4670k (not overclocked)

ASRock Z87 Extreme 4

Kingston HyperX Fury 16gb ram at 1866mhz (2x8gb kit)

Toshiba 1tb hdd (completely new)

Corsair cx750m (green label)

Gainward gtx 570 glh

OS installed is win 10 pro.