F12 fault
To be more clear, the most common cause of this fault is a shorted wire (L1 L2 L3/UVW inside the pecker head. What I do is set auto retries (A092) to 9 and watch for the phase loss fault to show, (F41/F42/F43). I’ll bet it’ll be right there when you open the pecker head. Sometimes you’ll have to look beneath where the wires go inside the shell of the motor, but it’s there.