What to do if the CPU fan does not turn

Failure phenomenon: A new configuration of the assembly machine, usually use everything normal. Only in the motherboard BIOS, the CPU fan speed is reported to be 0 rpm (Turn/min), while the actual fan operation is good.

Failure Analysis: Currently, the ATX architecture of motherboards basically support the fan speed monitoring function. This allows us to keep abreast of the CPU fan operation without opening the chassis. In this case, the symptom is obviously due to the failure of the BIOS to monitor the CPU operation information and error reporting. The causes of false positives usually occur in the following ways:

1. The power cord of the CPU fan is not plugged into the Cpufan (CPU fan) interface of the motherboard and is plugged into the other fan interface. This plug does not affect the normal operation of the computer, but the BIOS does not monitor the operation of the CPU fan.

2. The power cord of the CPU fan is poorly contacted with the corresponding interface on the motherboard, which is more common.

3. The CPU fan used is not a qualified product. Its motor has only two power cords, and no intermediate speed wire, which can not be feedback to the BIOS fan speed information.

4. The motherboard of the machine and the CPU fan in the speed of the electrical performance of the conductor indicators are different. So that the BIOS does not get the correct electrical information. However, this situation often results in a large gap between the fan speed reported by the BIOS and the actual speed. In the determination of the 1th and 22 conditions do not exist, generally do not appear to report the speed of zero.

Troubleshooting: After analysis, there is a general understanding of the causes of false positives, so solve the problem to be targeted. After checking, the power cord of the CPU fan was found to be plugged into the Bakfan (standby fan) interface. Plug it right into the Cpufan interface and then monitor it in the BIOS, everything is OK.