What was found
FLT#1621, LHR-BOS. (ETOPS) 'FUEL ACT XFR FAULT ( AUTO TRANSFER SYSTEM (ACT) 1), 2) ADDITIONAL CENTER TANK(S) (ACT) ); PILOT REPORTED THAT AFTER REFUEL PROCEDURE, ACT XFR FAULT CLEARED AND XFR FUNCTION WORKED NORMALLY ON FLIGHT TO BOS ( SEE DEFECT 4028937, ITEM 1 (INFO NOTED BY MX.)). REMOVED AND REPLACED REFUEL PRESELECTOR AS PRECAUTIONARY DUE TO PFR AND AVIATAR REPORTS.OPS CHECK GOOD. REF AMM 28-42-21. MX-4 UPDATED AND PLACARD REMOVED.'