CPU Fan Not Spinning Up

Darren

Darren

Moderator
Staff member
Hello all. Went over to a friend's house today to help him with his computer he just built. System won't POST and says CPU fan error. It tries to spin and fails, sometimes would randomly twitch and move a bit. Also sometimes it would spin up just fine but still say error and sometimes die out again.

It's an 3570K stock fan on a Asus Sabertooth Z77 board.

GS700 Corsair PSU.

Now we pointed a fan into the case, booted into BIOS, monitored temps and told mobo to ignore CPU fan speed. Booted right up into the disc drive and installed Windows with no issues. Got the computer working fine. Everything works great (RAM doesn't set to correct speed but I think I just need to reset that manually). Tested Minecraft and Furmark and everything was smooth as butter. Kept an eye on temps and never went above 54. I'm going back tomorrow to help. I tried every Fan header on the board and still got same results. Plugging a case fan into the CPU fan header fired it right up. Anything I can try? I'm almost positive it's just a bad CPU fan since everything else worked just fine.

Thanks.
 
wolfeking said:
I am 99% sure that it is the CPU fan being bad. But just in case make sure that it can freely spin ny pushing it with your finger. If it does, then the motor is burned out. Just get a cheap fan to replace it and you will be fine. Pretty sure you can get something at newegg for like $10

http://www.newegg.com/Product/Product.aspx?Item=N82E16835186051

that looks like a 1155 stock cooler. Check into it farther though.
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Yeah it freely moves if you push it with your finger, it just doesn't spin of it's own accord. I directed him to a Cooler Master 212 and he said that looked good, I'll let him know that it can be cheaper but I figure if you're going to get a new fan, might as well do it right.
 
its not the fan, its the board, go into the smart fan setting, and change it off auto, to pwm or voltage...try voltage first...if it spins up, your golden, if not do pwm. had that happen to me with a fan on my h50, it is a lower speed fan and auto for some reason just decided it was not going to work with that fan.
 
FuryRosewood said:
its not the fan, its the board, go into the smart fan setting, and change it off auto, to pwm or voltage...try voltage first...if it spins up, your golden, if not do pwm. had that happen to me with a fan on my h50, it is a lower speed fan and auto for some reason just decided it was not going to work with that fan.
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Ok I'll try that tomorrow thanks.

However that doesn't exactly explain why it does work sometimes but still says it's an error, even when it does spin up.
 
Try a different fan first and then if it still don't work then its got to be the connector on the board.
 
johnb35 said:
Try a different fan first and then if it still don't work then its got to be the connector on the board.
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As I said in OP, I tried it with a case fan in that slot and it worked fine. Also trying the CPU fan in a regular fan header yielded the same results.

Bad fan?
 
I support the view that it could be a bad fan. If you can pick up one of those 3-pin fan to molex adapters, try running the fan using one of those to see if it fires up. Or try the fan on another computer.
 
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