# Cpu fan starts then stops



## Clarkvan (Apr 3, 2007)

I just purchased a new setup for an old case... Athlon X2 4600, 1GB DDR2 667 and Asus M2V MOBO, Inwin 460 p/s... when I put it all together it worked fine (as far as I know this is my first time doing this alone) It showed the mobo and started setup but after about 10 sec the cpu fan (which starts up fine) will stop running... Im guessing its somthing to do with the bios??? how long will the cpu run safelywith no fan? I am to scared to leave it running long enough to figure it out!!??? 

Thanks, 

I hope Im not re-posting...


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## justpassingby (Mar 11, 2007)

Check that you plugged the cpu fan on the right place on the motherboard, the plug should be labelled cpufan, not chafan nor pwrfan.


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## Clarkvan (Apr 3, 2007)

yea it is for sure plugged in the right spot...


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## justpassingby (Mar 11, 2007)

Sorry, I felt I had to check :1angel: 

Now, you _could_ try to plug the fan on the cha_fan plug and see if it stays on, hopefully there's no default setting to keep it off while the case temperature is low.

I'm not very good at electronics so I can't help you much more, wait for someone else to give a look.

edit : or maybe you could try to quickly go in the bios and disable the fan speed control setting if it exists. Though I wouldn't risk leaving a cpu on for too long without the fan.


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## Deleted090308 (Jan 25, 2007)

Hi,
Is it only the fan turning off - or does the computer shut down? If so, you could have an overheating problem with the CPU. Did you remember to apply thermal paste between the heatsink and the CPU?

Nicholas


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## brothapig (Mar 8, 2007)

Is your MB smart fan capable? If so, it will vary the CPU fan speed according to the temp of the processor. Mine will run on start-up and then quit, just like yours does.


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## ebackhus (Apr 21, 2005)

Mine will start up at full speed and wind down to the point where it barely moves.


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## Deleted090308 (Jan 25, 2007)

Clarkvan said:


> I just purchased a new setup for an old case... Athlon X2 4600, 1GB DDR2 667 and Asus M2V MOBO, Inwin 460 p/s... when I put it all together it worked fine (as far as I know this is my first time doing this alone) It showed the mobo and started setup but after about 10 sec the cpu fan (which starts up fine) will stop running... Im guessing its somthing to do with the bios??? how long will the cpu run safelywith no fan? I am to scared to leave it running long enough to figure it out!!???
> 
> Thanks,
> 
> I hope Im not re-posting...


Sorry about not reading your post closely enough. During boot you could enter BIOS and keep an eye on the temperatures. If the CPU temp. rises very quickly - turn the computer off and try the suggestions above concerning fan connection and thermal paste. Also - make sure the heatsink is seated correctly.


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## Clarkvan (Apr 3, 2007)

Yea so it starts and then when the bios comes on then the fan stops and it says "cpu fan error" so the MOBO knows that somthings wrong ?!?!?


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## Deleted090308 (Jan 25, 2007)

Try running the computer with the mobo "out of" the case. There could be a problem with short circuits.


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