As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON ENGINE SHUTDOWN THE NR 1 TRANSFER BUS OFF LIGHT CAME ON. ACFT GROUNDED. ISOLATED TO FAULTY BUS TIE BREAKER C804. R & R C804 BUS TIE BREAKER NR 1 IAW MM 24-21-41. TESTS GOOD IAW SAME. NR 1 GCU CHECKS GOOD IAW INSTRUMENT TEST MM 24-21-81.