1) Release the UVW connector. Measure the resistance of U-V, U-W, V-W. If the resistance is not
equal to each other, the fan motor must has problems and need to be replaced. Otherwise, go to
step 2.
2) Power on and when the unit is in standby, measure the voltage of pin4-5 in feedback signal
connector. If the value is not 5V, change the PCB. Otherwise, go to step 3.
3) Rotate the fan by hand, measure the voltage of pin1-5, pin 2-5 and pin 3-5 in feedback signal
connector. If any voltage is not positive voltage fluctuation, the fan motor must has problems and
need to be replaced.