As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED. DURING DESCENT INTO DFW. AIRCRAFT WENT PARTIALLY INTO APPROACH PHASE. FLASHING ILS. MANAGED SPEED UNAVAILABLE. ALTERNATED BETWEEN GREEN DOT AND ATTEMPTED TO ACCELERATE TO .99 IN MANAGED SPEED. WOULD NOT COMPLY WITH CONSTRAINTS. APPROACH PHASE WAS STILL IN BLUE NOT ACTIVE. A/C ATTEMPTED TO NAV TO ILS LOC WITH APPROACH PUSH BUTTON NOT ARMED WITH LS PUSH BUTTON PRESSED. REPLACED FMGC1 AND ACCOMPLISHED SATISFACTORY OPERATIONAL CHECKS, PER AMM 22-83-34.