CPU fan turns on for a second and stops, PC does not start at all

bioscpufanmotherboardpower supply

I have checked my PSU and it works fine. When I turn on the MOBO, the CPU fan, case fans and the psu fan itself turn on for half a second and then turn off.

The PC remains off. The Bios light turns on for a fraction of a second and the debug led as well (for a fraction of a second). I am using a Gigabyte Z87-UD4H mobo and i5 4670K Haswell CPU.

Best Answer

Have you checked to see if the PSU is supported with HASWELL? their new power saving states require specific power supplies. I have found this out recently myself as I have experienced no post boot. I have to keep power cycling until it decides to boot. Ive found that disabling the C6 and C7 states do not help either. I ended up changing the CPU boot voltage within the BIOS.