Patent ID: 7991584

Claim:
A system for testing a fan interface of a motherboard using a fan simulator, the fan simulator comprising a fan connector and a signal conversion circuit, the system comprising: a parameter setting module configured for setting a duty cycle of a pulse width modulation (PWM) signal having a high frequency to be generated by a monitor chip on the motherboard, setting a desired rotation speed of the fan simulator, and an allowable error margin of the desired rotation speed and an actual rotation speed of the fan simulator, wherein: the monitor chip generates the PWM signal according to the duty cycle, and outputs the PWM signal to the fan connector via the fan interface; the fan connector transmits the PWM signal to the signal conversion circuit; the signal conversion circuit converts the PWM signal to a tachometer (TACH) signal having a low frequency by a frequency reducing circuit, and outputs the TACH signal to the fan interface via the fan connector; and the monitor chip receives the TACH signal from the fan interface and obtains the actual rotation speed of the fan simulator from the TACH signal; the system further comprising a diagnosis module configured for computing a difference of the actual rotation speed and the desired rotation speed, and determining that the fan interface passes the test if the difference is less than or equal to the allowable error margin, or determining that the fan interface fails the test if the difference is more than the allowable error margin; and at least one processor executing the parameter setting module and the diagnosis module.