1. S9 is no hash rate after replacing the fan. Fault light solid on.
Look at this FAN PWM: 0
There is no fan signal. It means the fan you replaced is defective. And you can choose another new fan to replace.
If you don't have, you can try to check the wire:
black = ground
red = input voltage
Yellow = Signal Speed
Blue = Signal PWM
The blue wire must be your FAN PWM, check the wire if it has a connection from the fan to the control board, or maybe you plug it wrong.
2. Only one fan was detected after replacing the fan.
The miner can only detect one fan or none at all. After a good fan is replaced, it still cannot be detected. The problem is the same when replacing this control board with a good machine. This indicates that the fan port of the control board is damaged and the control board needs to be replaced.
3. The speed is still not up to the standard after replacing the fan.
If the fan speed still cannot reach the standard fan speed after replacing the fan, it is recommended to upgrade the firmware and test again. if it still does not meet the standard, it is preliminarily determined that the control board is faulty, it is recommended to replace the control board or send it to the nearest maintenance center for repair.