TC reported hearing a loud sound while departing BSD1 . Train rolled back while departing BSD1 ~~~~~ 3533 found no abnormalities during depot movement. Checked all HV equipment & brakes - All OK. Found 1534 A1 CCD fuse blown. Limited movement & all M cars able to register powering torque. ER D/L & checked fault records but found no fault registered. Time of incident occurrence found to be at 0541 hrs. 1533/2533/2534 having no line voltage at the time of incident. Side Findings : Torsion arm bolt loose at the following location 3533 - A2 1533 - A2/B2 2533 - A2/B2    2534 - A1/A2 1534 - A2/B2 3534 - A2/B2 Water seepage found on 1533 FAD.  Kana. 05/09/2020.  1534 A1 CCD fuse replaced - Done. All torsion arm loose bolts rectified by replacing the conical washer & re-torqued to specifications - Done. Water test conducted on 1533 hatch cover but unable to duplicate leak. Purging of 1533 A/c 2 - Done. Brake check, propulsion check & APS voltage check - all OK. To further monitor during M/L revenue service.  Ridzuwan/Tarmidzi. 06/09/2020.