TC feedback after changing ends that car1668 both set #01 and set #02 air-con faulty. Unable to res et. Car was warm. TC feedback after changing ends that car 1 668 both set #01 and set #02 air-con faulty. Unable to reset ~~~~~ T226 3668(N) TC feedback after changing ends that car 1668 both set #01 and set #02 air-con faulty. Unable to reset. Car was warm. NEW NB CE: 1668 both acs faulty unable to reset n car was warm temp 27.1  From TIMS observed FC420: APS Power Supply Low Voltage. Changed out APS control unit and observed on TIMS, IGBT Gate On Signal was "Off". Conducted APS no power test ok. Swapped APS relay panel and APS control unit and TRSK1 to #2668, fault remained. Further checked found voltage before K line contactor was 750V, but the output voltage after the contactor had dropped to 623V.    Serviced the K-contact to no avail. Ops20 to change out the K line contactor. #1668 APS control unit Old S/N: 509RC000-4H New S/N: 506RC000-2H Notif: 2558089 Done by: Sanip/Koh/Jack 45296 To follow up 1668 K-contactor c/o  Changed out K contact at #1668. No further fault. APS Power/no power test ok. Aircon able to run and cut in/out. Depot shunting ok. Monitored over a few hours, fault did not recur. Done by: Saini/Haslan/Asruddin 45297