As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
RT PNEUMATIC ISOLATION VALVE LIGHT STAYS ON REGARDLESS OF SWITCH POSITION, NO IND OF RT DUCT PRESS CANNOT OPEN START VALVE CANNOT GET N2 ROTATION. REMOVED AND REPLACED RT ISOLATION VALVE, CYCLED SWITCH SEVERAL TIMES, OPS CHECK NORMAL, DUCT PRESS NORMAL PRESS FOLLOWS VALVE CMD.