What was found
BLEED AIR DUCT PRESSURE, LT- 22 PSI, RT- 45 PSI, CLIMBING THRU FL320. IN LEVEL FLIGHT DUCT PRESSURE STABILIZED AT LT- 30 PSI RT- 45 PSI AT FL360, CRUISE FLIGHT, N1 88.5/88.4, N2 91.6/91.9 LT DUCT PRESSURE FLUX TO AS LOW AS 21 PSI RT STABLE AT 45 PSI. ACFT GROUNDED. PERFORMED FIM 36-10, TASK 801, STEPS A- F(2)(C)(6). FOUND NR 1 PRSOV TO BE INCORRECTLY IN THE FULL OPEN POSITION WITH NR 1 BLEED SELECTED ON AND SYS PRESSURIZED BY APU, ALSO AFTER SELECTING NR 1 BLEED TO OFF, PRSOV DID NOT FULLY CLOSE BUT REMAINED HALF-OPEN. REPLACED NR 1 PRSOV IAW AMM 36-11-04-000-801/-400-801. OPS CK AND LEAK CK GOOD. GROUND VERIFICATION CK GOOD IAW AMM 36-11-00-700-801.