As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE FLIGHT CREW REPORTED THAT THE NR 2 ADC INDICATED AN INTERMITTENT OVER SPEED WARNING INFLIGHT & ON THE GND. TROUBLESHOOTING OF THE NR 2 FOUND IT TO BE DEFECTIVE. THE DEFECTIVE ADC WAS REMOVED PN 7000700-668, SN 00078756 & A REPAIRED UNIT WAS INSTALLED & TESTED IAW AMM 34-10-10.