What was found
CABIN PRESS AUTO INOP LT ILLUMINATED ON GROUND AFTER ENG START/TAXI. CABIN DIFF CLIMBED TO 4 PSI DIFF. NO CHANGE TO CONDITION W/ SWITCH TO AUTO 2. OUTFLOW VALVE REMAINED CLOSED. CABIN ALT AUTO 2 EICAS MSG DISPLAYED. CPC NR 2 FAULTED ON BITE TEST. MANUAL MODE OK. PERFORMED FIM TASK 21-31 FT 809 AND FIM 21-31 FT 803. CABIN PRESSURE CONTROLLER NR 1 FAULTED. REPLACED CPC NR 1 PER AMM 21-31-02. OP'S CHECKED GOOD.