What was found
A/C PRESSURIZED NORMALLY ON DEPARTURE. AFTER 10,000 FT, RECEIVED AURAL AND EICAS WARNING FOR CABIN ALTITUDE. CABIN ALT=10,400FT, DELTA P= 1.7 OR LESS AT 14,000. FIRST ACTION-- DEFERRED AUTO PRESSURE CONTROLLER--2ND ACTION---CLEANED ELECTROPNEUMATIC AND PNEUMATIC OUTFLOW VALVES, OPS CHECKS GOOD