Dear Pui,
A little more info would be necessary. F84 is Shortened to PE, could be caused by the motor. If the Motor is OK, it could be caused either by the current converters or the cable or the current measurement circuit at the 3.0124 PCB. The Failure F 208 is Blocking failure, that could also be caused by the motor, the Current converters, the IGBT, the triggering units…
Are the failures permanent or sporadic?
Is the motor OK?
How about the IGBT modules?