As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
NR 2 ENGINE LOGGED FAULT NR 73 30312 THE START SWITCH SIGNAL AND ARINC BUS DATA DISAGREE FOUND WHILE ACCOMPLISHING T/C 78273000 INTERROGATE THE FMC CDU FOR ENGINE FAULTS. REMOVED AND REPLACED NR 2 ENGINE START SWITCH. CONFIRMED CORRECTED REF FIM TASK 73 24 00 810 813 F00 REF WDM 74 31 11.