As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
NR 1 ENGINE HAS FAULT CODE 74-30971, THE APL INPUT VOLTAGE FOR THE LEFT EXCITER IS OUT OF RANGE. ACFT GROUNDED. ACCOMPLISHED IGNITION SYSTEM AUDIBLE TEST WITH NO FAULTS FOUND IAW AMM 74-00-00. SUSPECT FAULT CAUSED BY MOMENTARY POWER LOSS DUE TO OTHER FAULTS LOGGED ON SAME FLIGHT LEG 0 IAW FIM 74-21 TASK 801.