If power fan never rotates when ATV is in operation, the fan should be removed and tested first mechanically by hand to exclude bearing malfunction, then electrical test using external 48V DC.
Attached picture shows cable that connects fan with X22 connector on power board.
Pin 1 and 2 on X22 provides 48V DC for the fan (pin1 +, pin2 -). Pin 3 is dedicated for fan feedback.

Released for:Schneider Electric United Arab Emirates