TC spotted arching at Front M2 car undercarriage.Rear T262 did line clear feedback to sign of arch ing from the undercarriage.SM(SOM) took cab ride on T443 f eedback no sign of arching from the track side and train und ~~~~~ TC spotted arching at 2553 car undercarriage.  Rear T262 did line clear feedback to sign of arching from the undercarriage.  SM(SOM) took cab ride on T443 feedback no sign of arching from the track side and train undcarriage. RFP NB CE: 3553 No abnormality found  check 1553/2553 ccd fuse at 1553 A1 blown replace done. check Undercarriage HV Equipment, Aircon, earth return cable, propulsion equipment,APS done. found 1553 APS relay having sign of flashover required to replace. Conducted APS,No power test ok. propulsion static test ok. Done by Zulq/asruddin 45138 To replace APS relay at 1553  1553 found the relay oxidation, Replaced all the relay(APS) and Function test power and no power test ok Done by Rizman/Sanip 01.08.23