As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE ACCOMPLISHING TC 78273000 FOUND FAULT 73-31162 FOR THE NR 2 ENGINE. THE MECHANICAL OVERSPEED PROTECTION SIGNAL IS OUT OF RANGE. ACFT GROUNDED. TROUBLESHOT IAW FIM 73-25 TASK 805. ALL RESISTANCE CHECKS PASSED. FAULT HISTORY ONLY SHOWS THE FAULT OCCURRING SPORADICALLY. REMOVED AND REPLACED THE EEC IAW AMM 73-21-60-000-801/73-21-60-400-801. OPS CHECKED GOOD. PERFORMED TEST 13 ENGINE RUN, EEC BITE CHECKED IAW AMM 71-00-00-700-808-F00. TEST PASSED.