New build fans turn on and off

Step two: The Opening

Just built a new pc earlier today and when I turn on the power the fans on the cpu heatsink and case fans just go on and off til I unplug the power


The specs are i5 2500k cpu, hyper 212+ heatsink/fan, antec 750W psu, storm scout case, P67A-G43 mobo, GTX 560Ti graphics


Steps I've tried to solve this issue is:

1. Checked cpu to see if any bent pins and that came back a negative SO i reseated the heatsink/cpu and still same issue.

2. I tried just having cpu/heatsink and psu installed nothing else. Still same issue

3. I even took the mobo out and laid it on the anti static wrapping that it came with from the mobo to see if anything was shorting it out in the case and still had same issue.

4. I took my old psu from this computer I'm typing from which is a OCZ 600W psu and I had the same issues as I did with the new psu.

Another Thing I'd like to mention is that speaker thing that comes with mobo I think is where it came from anyway I plug that into the mobo and not once have I heard a beep from it. So is it my mobo that is possibly doa or cpu?

Anyone have any suggestion because I've been trying to figure this mess out all night.
6 answers Last reply
More about build fans turn
  1. You could try flashing the bios in the motherboard otherwise I think this is the tachometer controller on the motherboard that is trying to speed up your fans. I don't think it is seeing the speeds or something along that line. This would be an RMA issue most likely.
  2. So is this most likely just a bad mobo that needs to be replaced? Because when I had the power going The LEDs on the fans etc were working so was the CPU phase LEDS next to the processor it was going up to 3 and 4 lights. Not sure if that makes and difference.
  3. Well I haven't seen many motherboards that turn off fans if the temps drop below a certain temp. 99.99% of the time they would never shut off being they have electricity flowing through them and thus create heat as long as they are on. This is what leads me to thinking it is either a bios or a motherboard failure.
  4. I"m just hopeing that nothing else was compromised and that it was just the mobo. It seemed like it was in a infinite power loop cause it would just go on and off nonstop stil I unplugged the power.

    From what I can tell there is no burnt marks on the cpu, ram, graphics etc. So I'm confident to say 99% defective mobo.
  5. Sounds like a reset switch that is cycling/grounding. I'd disconnect the reset switch from the motherboard and see if it rectifies.
  6. Well I tried the above post suggestion and no difference. So Yesterday I just RMAed the the mobo. Now I have to wait 2 weeks til new one comes.

    Someone suggested to me it could've been a cpu failure. But my question is if this was the case wouldn't the heatsink/fan, fans in case, fan on gpu continue to run at full speed and not go on and off nonstop til I unplugged the power?
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