As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
BLEED AIR VALVES LT CIRCUIT BREAKER TRIPPED, P6-4, NR 7. ACFT GROUNDED. GVI P6-4 CIRCUIT BREAKER PANEL NO FAULT FOUND RESET CIRCUIT BREAKER. CIRCUIT BREAKER TRIPPED AGAIN. DISCONNECT DP1102, CIRCUIT BREAKER STAYED IN. SUSPECT M1180 ENG 1 BLEED AIR REGULATOR. REPLACED NR 1 ENGINE. BLEED AIR REGULATOR, IAW MM 36-11-03. ACCOMPLISHED INSTALLATION TEST IAW SUBTASK 36-11-03-860-004. CIRCUIT BREAKER REMAINS IN.