CPU fan won't spin

I replaced my old MB with a Gigabyte GA-P45-UD3L and used my old Intel E8400 CPU. The CPU fan will not spin. I have tried 2 different fans and this is my 2nd MB. I also have a 600W power supply. I have removed everything but the cooler and fan. Any ideas? I'm stuck.

 

try disabling any smart fan options in the bios
you can " hot Wire the fan to a Molex connector on your psu if you need to

 

Did you run it long enough to let the CPU warm up - some fans don't kick in until they're needed (it seems like you would know that, but just in case ... and it's hard to imagine what else it might be). I see from your MB specs that your MB has CPU fan speed control. As rjc862003 says, you might find that disabling the speed control gets things going, or just run the PC until the CPU warms up, if you haven't already. I assume it runs all right, other than the fan...
Perhaps the fan is not compatible with the MB, but that's outside my know-how (hard to imagine it would be though).

 

Welcome to the forum Are you saying the CPU fan didn't spin with your old mobo?

You could plug your CPU fan into a system fan socket on the motherboard,this is what I do then manually set the fan speed with a potentiometer I don't like fans that speed up and slow down.

Get a multimeter and check the voltage coming from the CPU fan socket,just boot into bios so there's no chance of your CPU over heating then check the voltage either by really carefully touching the pins in the socket or cut a fan off an old fan and take the reading from the wires.

I doubt its an errant bios setting I've never seen one that can disable the CPU fan its too critical.

 

After replacing 3 MBs, 2 fans and coolers and much frustration, it turned out to be a bad "bridge" in the 600W power supply. Everything was getting power except the CPU fan! I replaced the power suppy and all is well.
Thanks for your reply.

 

Great!

Good to hear you sorted everything out!

 

The old bad-bridge-in-the-power-supply trick!!
Someone should make a list of all problems, and all possible solutions. Then we could go through and tick them off. (Probably be millions!!) :confused
And this would probably be an addition to the list!
Well done on figuring it out.