As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT 579 - MEX-CUN - AIRCRAFT RETURN TO PLATFORM DUE TO SIF LIGHT TURN ON AND BOTH FLIGHT DIRECTORS DISAPPEAR ON TAKEOFF MODE. DURING CHECK IT WAS DETECTED THAT THE RELAY R2-6 MAINTAINS IN FLIGHT MODE ALL THE TIME. RELAY WAS REPLACED AND TESTS WERE PERFORMED IAW MM 34-19-00. (M)