What was found
MACH TRIM LIGHT ILLUMINATED IN FLIGHT. DOES NOT EXTINGUISH ON MASTER CAUTION RECALL/RESET. AFTER A SHORT DELAY AND MULTIPLE RESET ATTEMPTS, THE MACH TRIM LIGHT DID EXTINGUISH. OPERATES AS EXPECTED NOW WITH MEL 22-5C. SUSPECT MASTER RECALL/RESET ISSUE. GROUNDED - YES. NO FAULTS LOGGED IN FCC-A. COULD NOT DUPLICATE MALFUNCTION. ALL MACH TRIM AUTO, INTERACTIVE & SURFACE TESTS PASS. REF BITE GROUPS 10,13, 33, 48, & 57.