What was found
CABIN ALTITUDE AND DIFFERENTIAL PRESSURE GAUGE INDICATES HIGH CABIN PRESSURE DIFFERENTIAL AND LOW CABIN ALTITUDE DIFF PRESS INDICATED 8.6 AT FL390 DOWN TO FL290 LOCKED FOR DIFF PRESSURE GUAGE R&R UNLOCKING FOR MX INDICATOR, CABI OFF 29-3111-9-0001 7669 ON 0000 INDICATOR, CABI OFF 29-3111-9-0001 7669 ON 29-3111-9-0001 9273 REPLACED CABIN ALT DIFF PRESS INDICATOR REF AMM 21-33-02-401. OPS CHECKS GOOD. PARTS USED: 29-3111-9-0001,QTY :1 ROTABLE PARTS CHANGE WAS INDICATED - TT # 1541825 SN OFF 7669. PERFORMED DPCP BYTE #1 & #2 IN REF WITH AMM 21-31 TASK 801. DCPC #1, FLIGHT LEG 38- LO INFL/HI LEAKAGE.. DCPC #2 FLIGHT LEG 72-DADC #1 INVALID. SYS STAT CURRENTLY NORMAL, NO FAULTS. ACP FIM 21-33 TASK 803. ALL TESTS FALL WITHIN LIMITS. NO. FAULTS.