What was found
CABIN ALT & CABIN ALT LIGHTS ILLUM, EICAS MESSAGE CABIN ALTITUDE WAS DISPLAYED. UNABLE TO RESTORE CABIN PRESS USING MANUAL MODE, O2 MASKS DEPLOYED. ALSO WAS PRESENTED EICAS MSG FWD CARGO A/C AND FWD CARGO A/C INOP LIGHT ILLUM WHEN THE FLT ARRIVED LT PACK WAS FOUND TRIPPED BY "FWD A/C CARGO FAULT" AND RT PACK DEFICIENT. FOR LT PACK, PACK FLOW AND CARGO A/C CONTROLLER (PFCAC) WAS R & R IAW AMM AND "AUX TEMP CONTROLLER" REPLACED IAW AMM WITH SAT RESULTS. FOR RT PACK, PRIMARY & SECONDARY HEAT EXCHANGERS WERE REPLACED IAW AMM. CONTAMINATION FOUND IN SECONDARY EXCHANGER, IT WAS REPLACED. LOW LIMIT VALVE PACK RT IAW AMM WITH NORMAL RESULTS. ACCOMPLISHED PRESSURIZATION & TEST OF PACKS, PRESSURIZED TO 4 UNITS OF DI