TC reported Front DT train door not proven closed. A4 door opened and closed few timesto no avail.Staff(YIS) checked and feedbacketrained to platform. DIRBS operated for train to proceed to ~~~~~ Tims showed 2x door close operation timeout at #3627-A4 door. Fault trace and ER downloaded to PTU006 door gap 40mm & 48mm. Checked J-rail and door guide - no FOD. Found RHS door leaf slight wobbling. Removed door leaf found 2x main rollers bearing no good. Replaced door rollers and serviced doors. Door resistance 6kg - ok. Door cyclic test 10x - ok. Door open & close timing ok. Door close s/w and door lock s/w rigging checked ok. Done by Koh/Joshua. 14/05/21.