My CPU fan turns off after computer wakes from sleep mode

I have a rather confusing problem with my newly built PC. The other day I was using my computer and it randomly shutdown on me without warning. I tried to turn it back on but the fans would only start to spin up but it wouldn't post. I let it sit for an hour and everything seemed fine. Then it happened again yesterday. This time I took notice of every detail. The computer seemed pretty hot. I did some testing and I learned that the CPU fan isn't turning on after I take the computer out of sleep mode. I tried all the settings in the BIOS and checked connections but it persists. I also uninstalled all the programs on my system that have fan controllers built in and tried swapping PSUs. Sleep mode is currently disabled. Has anyone ever seen this before? I think that the fan isn't getting enough voltage to get going because it starts to spin and quits about 50%. Sometimes it turns on sometimes nothing. The scary thing is my motherboard didn't give me any warning about the temps and for some reason my computer doesn't report the correct temps in any of my utilities. Bad sensors? Bug in BIOS? I don't know what else to check. Thanks


Gigabyte GA-F2A88XN-Wifi
AMD APU A8-6500
Corsair Vengance 2133
Crucial M500 240gb
Noctua NH-L9a
pico-psu 160XT

Yeah I double checked the manual and it is clearly labeled as the CPU fan header. The motherboard is a Mini-ITX and it only has two fan headers.

I tried messing around with my power settings today in Windows 7 and I still can not figure out what the issue is. My gut tells me that it is a BIOS issues because I also can't get an accurate temperature read with any software.

Does anyone have any input?

Hi. I'm having exactly the same problem down to every little detail. My motherboard isn't warning me either, I've just set a 60c temp limit which forces an instant shutdown if it reaches 60 degrees. The only think that has worked for me is use a different header and disable fan control completely, because it would just keep overheating and shutting down shortly after a resume from sleep. Did you ever find a solution?

My system:
AMD FX-8320 CPU
Gigabyte GA-970A-UD3P Motherboard
8GB G.Skill Trident-X 2400MHz RAM

I have since learned that Windows 7 has a lot of issues with sleep mode on a lot of motherboards. It's a common problem that a lot of people have given up on trying to fix. The fan on my computer wasn't turning back on when waking up. Other components were having issues too. I have disabled sleep and the problem has "gone away". I wish that I could use sleep though. I use log off instead.

My board in particular has issues giving an accurate CPU temp which adds to the problem. The only way I can get an "accurate" temp is in the BIOS. Some programs report 100C at idle others are reporting 15C at idle. I think it's probably a BIOS bug. I updated to the F4 BIOS but it's the same.

I'll never buy a Gigabyte board again. I specially resent that when I bought the board it did not come with the updated BIOS and I had to buy an older CPU to make it work.

I wonder mine is measuring correct. Core Temp: 23-27C idle. Ambient should be 23-24C. Specs are current.