As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
RIGHT PACK OFF LIGHT ON STAND BY-CIRCUIT BREAKER-RECYCLING SWITCH NO HELP NO OTHER INDICATIONS CYCLED RT PACK CONTROL BREAKERS PRIOR TO APU START UP. RIGHT PACK CAME ON LINE OK WITH NORMAL INDICATIONS AND BLEED PRESSURE INDICATIONS. PACK RAN OK ON GROUND PRIOR TO DISPATCH FOR ONE HOUR. REPLACED FLOW CONTROL VALVE. WITH RIGHT PACK SWITCH OFF NO PACK OFF LIGHT OR EICAS MSG. RECYCLED RIGHT PACK SWITCH OPERATED NORMAL