As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING PREFLIGHT FOUND "ALTN POWER-CHAN B" CIRCUIT BREAKER TRIPPED. ACFT GROUNDED. VERIFIED EEC 1 TRIPPING CIRCUIT BREAKER, ALSO, REPLACED NR1 ALTN PWR CIRCUIT BREAKER. R & R NR 1 ENG EEC IAW 73-21-60. NR 1 EEC, OP CHECKED NORMAL. REF MM 73-21-00.