As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
OVERSPEED TO ACFT PAST MMO TEMPORARILY FOR 2 SECOND AT TOP OF DESCENT VNAV SPD DID NOT ENGAGE AS IT SHOULD ON THE COMMON VNAV PACKAGE. GROUNDED YES. CAPT REPORTED OVERSPEED OF APPROX 5KTS FOR 2 SEC. OVERSPEED WITHIN LIMITS PER MM 05-51-04 PARA G NO INSP REQ. BOTH FMC'S OPS TEST NORMAL PER MM 34-61-00-710-801 NO DEFECTS NOTED. VERIFICATION FLIGHT SUCCESSFUL.