Laptop CPU Fan Problem

[IceQB]

Ok, so i have this HP NX5000 i fixed up. Only thing now is cpu fan not working, replaced it - still nothing.
Problem now is its overheating & switches off when it does.
Have looked at everything i could think off, is there a sensor that detects temp & switches on fan?
Any / all help appreciated

 

[Savage152]

I would guess there is either a sensor, or the bios that is responsible for this function, have you tried powering up the fans on a battery or power supply, also do they both have the same pin layout? Maybe also check your Bios for settings you may have got wrong, sometimes you can set the fan target too high and it could overheat?

If push comes to shove you might just need to tap power off the mobo somewhere and leave the fan running permanently?