What was found
FLT 447, BOS-TPA, DIVERTED TO JFK, BLEED 1 FAIL EICAS AT FL300, BLEED 1 PSI ABOUT 7 PSI, UNABLE TO MAINTAIN CABIN ALTITUDE. CLIMBING 800 FPM WITH CRUISE THRUST. FAULT CODE 36111200AM1 FOUND ON CMC. REMOVED AND REPLACED NACELLE PRSOV IAW AMM 36-11-03. OPERATIONAL CHECK OK. NO FAULT NOTED ON NR 1 BLEED SYSTEM. (S)