Pax feedback to YWT air-con condensationat front M1 car. MSL checked and confirmed air-con condensa tion at car 1628 near A1 door. ~~~~~ 1628 Pax feedback to YWT air-con condensation. MSL confirmed air-con condensation at 1628 near A1 door. OE request to troubleshoot 1628 near A1 condensation and replace air filter at evaporator if dirty. It was reported by pax quite frequently  1628 A/C 1 filters replaced with new. Purged A/C 1 drain pipe. Tested A/C operation & monitored for 2hrs for condensation - OK. Lee KH 44724