This is a summary of common generic problems with fans (Bitmain Antminer S19 series, Z15 series, D7, L7 and other new models)
1. the Arithmetic Interface Shows That the Fan is Abnormal Or the Speed is 0.

Causes and Treatment
The Antminer S19 has four fans, and the control board’s fan number (FAN1, FAN2, FAN3, and FAN4) corresponds to the user panel’s fan number. Replace the appropriate fan after first determining which one is abnormal; if the issue persists after doing so, the control board is likely damaged, so you should take it back to the manufacturer for repair.
2. Too High Speed

Causes and Treatment
The corresponding fan must be replaced because the damaged fan.
Contact us at any time if you have any questions.