What was found
BLEED PRSOV LIGHT STATIS MESSAGE ON TAXI OUT. SNAPSHOT SHOWS HI PRESSURE SOV CLOSED AT IDLE. BLEED OFF ENG-LT MESSAGE AND OFF LIGHT ILLUMINATED IN BLEED SWITCH. CYCLED SWITCH, NO HELP. ACCELERATED TO APPROX 50 PERCENT, N1 NO CHANGE. DUCT PRESS IS ZERO. LT BLEED INOP, ACP MEL FOR 3611K AND DEFERRED ENGINE IDLE IAW MEL TEXT. PRESS CD L-PRSOV WITH SHOP AIR-VALVE OPEN & CLOSED NORMAL, PRESSURE CHECKED SENSE LINE FWD TO PRSOV CONTROLLER, FOUND CONTROLLER LEAKING EXCESSIVELY. PRSOV LOCKED-OUT REF MEL. REPLACED PRSOV CONTROLLER PER MM. SYSTEM TEST PASSED AND OPERATIONAL TEST OK WITH ENG RUN. MESSAGE ERASED AND NO FAULT ON THE MAT.