What was found
CLIMBING THROUGH 12000FT, THE NR 1 BLEED VALVE FAULT LIGHT ILLUMINATED. TURNED OFF & ON BLEED VALVE SWITCH MULTIPLE TIMES WITH NO RESET. FAULT LIGHT REMAINED AFTER MULTIPLE ATTEMPTS. FOLLOWED QRH WITH NO SUCCESS. . VERIFIED NR 2 PACK OFF. JUMPSEATER IN COURIER HEARD A LOUD POP ON LEFT SIDE OF THE ACFT. BITE CHECKED THE NR 1 CONTROLLER, CURRENT FLIGHT FAULTED C- CONTROLLER, TROUBLESHOT FAULT IAW TSM 36-00-01, FIG 101, NO DEFECTS NOTED, RAN APU BLEED AND CHECKED FOR PRECOOLER BYPASSING, NOTHING HEARD OR FELT. PRESSURE TESTED HP PRSOV SENSE LINE FROM VALVES TO PRESSURE SENSORS, CHECKED GOOD, PRESSURE CHECKED FAV SENSE LINE AND FOUND FLEX LINE BLOWN, R & R THE SENSE LINE IAW AMM 36-11-16-04-04, LEAK AND OPS CHECKED GOOD,