Fans not spinning

[Kelemvor]

Hey there,

I just replaced the CPU on a PC of mine. I noticed that the heat sink fan and case fans only spin for about 12 seconds when I turn on the PC and then they shut off.

It's an older P4 2.666 machine. I don't know if that's normal and they will just turn on and off depending on the internal temperature or if something is wrong.

Anyone have any info for me? Not sure if this is controller by BIOS and I should look for a setting in there or what but I don't want to burn out the CPU or anything like that obviously.

Thanks.

 

[mpilchfamily]

The fans should always spin. If they are connected tot he motherboard then there may be a problem with the board.

 

[Kelemvor]

Yeah, the power cord from the fan to the MB is in. When I first turn on the machine everything spins up. They after 12 or so seconds when the Windows XP Splash screen comes up, they stop spinning.

 

[jamesbond007]

Are you sure they completely stop? As in, you have a visual of them and the blades are stationary?

Only reason I ask is because many OEM systems (read Dell, HP, etc) throttle the fan speeds way back when the OS starts up. I once worked on a HP where it sounded like a jet until the OS started and then it went dead silent. Not doubting you, just covering all the bases. 🙂

Also, is the CPU officially supported by the BIOS? Perhaps a BIOS update is in need? If there is such a fan throttling program in the BIOS, perhaps it doesn't know what to set the fan speeds to for an unknown CPU type.

Good luck!

 

[Kelemvor]

OK, I figured it out. There was a setting in BIOS for the fans. Normal, Quiet, and On.

It was at Normal and I changed it to On and now they are going all the time. I guess Normal must have been based on temperature or something.

And yes, they were totally stopped because I had every opened up and was looking right at them.

Thanks.