What was found
ENROUTE AT FL340 NOTICED EARS POPPING AND CABIN DIFFERENTIAL NEAR 6 WITH CABIN ALTITUDE AT 9000. 10 MINUTES LATER RECEIVED CABIN ALT HIGH EICAS. DONNED O2 MASKS, RAN QRH AND DESCENDED TO 10000 INITIALLY. EICAS REMAINED. DESCENDED TO 9000 AND EICAS WENT OUT. ONCE AT 9000, CABIN PRESSURIZED TO ~7000 . AT NO POINT DID CABIN ALTITUDE EXCEED 10,000. FOUND FLOW CONTROL VALVE FAULTED LAST FLIGHT. REMOVED AND PARTIALLY INSTALLED FLOW CONTROL VALVE REF AMM 21- 51-01-2. FINISHED INSTALL OF L/H FLOW CONTROL VALVE REF AMM 21-51-01-2 FLO CONTROL FAULT LIGHT REMAINS ON BOX DURING RTS. FOUND BROKEN WIRE TO CANNON PLUG D4128 ON L/H FLOW CONTROL VALVE .RETERMINATED PINS AT CONNECTOR D4128P AND REASSEMBLED IAW B757 SWPM 20-61-00 AND WDM 21-51-12. NEEDS OPS CHECK.COMPLETED OPS CHECK OF L/H FLOW CONTROL VALVE OPS REMOVED AND REPLACED LH PRIMARY AND SECONDARY HEAT EXCHANGERS AND RAM AIR DUCT TO COMPLY WITH TSI 21-50/8611 REF 757 AMM 21-51-02-4.