What was found
AFTER BLOCK-OUT, COMPASS FLAG CAME INTO VIEW ON CAPTAIN'S HSI. COMPLIED WITH QRH PROCEDURES, RESOLVED COMPASS FLAG NO LONGER IN VIEW. AFTER TAKEOFF COMPASS FLAG REAPPEARED. RETURNED. REPLACED FLIGHT INSTRUMENT ACCESSORY UNIT PER MM 34-62-061-4, CHECKED NORMAL. REPLACED AUTOPILOT TRASFER RELAY, AS A PRECAUTION, ALSO REPLACED NR 1 INSTRUMENT TRANSFER CIRCUIT BREAKER PER WDM 34-21-03, TESTED NORMAL. COMPASS READING MATCHED WITH STANDBY COMPASS READING, ALSO CIRCUIT BREAKERS STAY IN, NO FLAG IN VIEW.