Uncontrolled CPU fan speed

Make sure you have used the proper Fan connection on the motherboard and that you used all the pins in it. Usually it consists of 3 to 4 pins for CPU fans. Does your Fan have 3 pins? If not then it is not compatible for Fan Speeds. Also check your BIOS for Fan adjustments. Hope this helps.

Check your motherboard for swollen capacitors. The HP small form factor computers are notorious for blown capacitors on the motherboard. I had a model DC5100 where the fan ran at top speed all the time. There was a swollen capacitor located at the end of PCI slot 1. I believe it is C469. It is a 1000uF 6.3volt cap. I replaced the capacitor and that fixed the problem. Keeping the computer cool will lengthen the life of the capacitors. It is wise to periodically remove the dust so cooling air will flow. Especially in small form factor models. How ever, once a capacitor goes bad, the only fix is to replace it. A blown capacitor will be swollen. The normally flat top will be curved upward and possibly leaking a brown crusty material.

Have changed CPU fan once but it is not proper so I changed the same one earlier used but from that time the CPU fan speed is uncontrolled the speed is not vareying as per the processor load. I will go to the setup and adjust speed to a different value but no change is ocuured in the fan speed.I think some problem occured in mother board. Pls find a solution for this problem. Thankyou .I have checked the bios and change the fan speed but no change is come on the fan speed and the connections of the fan are correct please find a solution. the fault is maybe in the motherboard