What was found
LAX - FLT 3123 - DURING INITIAL ROLL YELLOW FLAG INDICATORS ON BOTH ANNUNCIATOR UNITS FLASHED, CONFIG WARNING, F/O ALTIMETER FLAG, AND RUDDER LIMIT LIGHT CAME ON. MAINTENANCE FOUND WEU FAILED. WEU WAS REMOVED AND REPLACED, ALL SYSTEMS OPS CHECK GOOD. AIRCRAFT WAS RETURNED TO SERVICE. (M)