Fan doesn't work on laptop

[tunaep]

Hi
I have several laptops all the same make which I have purchased to refurbish but although all of them boot none of them have a working fan. Can anyone explain how the fan is controlled on a laptop motherboard ? there is no temp sensor I can see under the CPU.
Mobo is a Time 8375 (Dixons group generic) AMD xpm 2000 I have naturally swopped several good fans CPUs memory etc . Mobos are fully stripped on the desktop. I have Googled for hours until I went blind lol

 

[rvnguy]

tunaep,

The fan is normally temperature controlled (it starts when a pre-set temp is reached). Normally, these donot run continuously due to power management and will cycle on and off as required.

The sensor is most normally the core sensor on(in) the chip(CPU). Some BIOS's have a monitor temp area that you can view the temp.

If you have one out of the machine, and have access to the voltage that is usually displayed on the fan, you could test that the fan runs.


rvnguy
"I know everything..I just can't remember it all

 

[tunaep]

I have naturally used fans that are tested already. There is no problem with the fans .
If the temp sensor is actually in the CPU then could the cpu run the laptop ok yet just not trip the fans to work ? maybe the cpu has been damaged already previously when the fan failed ?

 

[franklin97355]

Does the computer boot? If so you could run diagnostic software.

 

[tunaep]

hi franklin yes as I said in the original post ALL the mobos boot and work fine .
what diagnostic software would you recomend that would find the reason for the fans not working ?

 

[franklin97355]

http://mbm.livewiredev.com

might work.