Pax feedback to staff(CBR) unusual soundfrom the ceiling of car 1644. Staff(WDL) checked and confir med no abnormalities found. ~~~~~ 1644 Pax feedback to staff(CBR) unusual sound from ceiling. Staff(WDL) confirmed no abnormalities found. CE : 1644 ac 1 isolated, temp 29.4 1644 knocking noise from Ceiling whenever APS fault occur ac 1 isolated, APS n noise cleared.  1644 a/c 1-1 compressor motot found shorted to ground. FC APS fault & over current. Tagged and isoated a/c1-1. Notif 2518757 raised to HM for c/o.  Sarma/Sugu/Alan/Shafie 45165 Notif 2518757 Name                          : SARMA & SUGUMARAN Date of Occurrence            : 27/08/23 Last Service Date             : N.A EMU / Equipment / Location    : 1644 / A/C / 1-1 Equipment Serial No. (if any) : N.A Description of fault / cause  : COMP SHORTED TO GROUND Measurements (if any)         : N.A Required Rectification        : Required Change out