Train encountered power fault at Rear M1car while departing station. Reset-ok. ~~~~~ 1528 encountered power fault departing station. Reset-ok.  1528 checked all earth brushes length within criteria. Swapped #1528 propulsion control unit (PCU) to #1527. During limited movement at maint. pit, observed spark & smoke at #1528. Found #1528 TM1 shorted to GND. Notif 2279087 raised to RSW. Isolated PRCB & tagged.  Ridzuwan/Nelson 44340 Name                              : Nelson Date    Of    Occurrence          : 24/05/2021 EMU/Equipment/Location            : 527/528 / traction motor /                                       1528 TM 1 Description Of Fault/Cause        : 1528 TM 1 short to Ground,                                       spark and smoke observed                                         during limited movement at                                       maintenance pit.(CM01)