A' side cab door repeatedly opened by itself. TC recycled cab door - ok. Train departed at 5kph. TC recycled cab door again - ok. Train ATPM to next station. Nofurther abnormalities. ~~~~~ A' side cab door repeatedly opened by itself. unable to >5kph.  L3From ER. LDC logs and ATS playback, cab was occupied at 3660 at Marina bay unable to achieve >5kph for 2 mins. Target speed was 60 kph throughout. ML1-3 was satis. TC cycle cab door when train stopped. This triggered an EB by CBTC (normal behavior) As train only able to 6kph, postulate unable to propel at P1. Measured SR, AMR1-2. 3660 AMR2 resistance 30ohm. SNR TNR and WFR check satis.  Replaced preventively AMR-1 and AMR-2 at 3660. In depot, cab door cx found no anomalies. Door open PB ok. Replaced 3660 A/S CDTR3A, CDOR2A-1 and CDOR1A preventively.. Performed MLT. 659/660 passed MLT with no anomalies powering satis in auto mode Cab door cx in mainline satis Train able to reach target speed Cleared to release by DRSM. Done by Luke, Johari, Ashwin. 6/2/2024