What was found
SUPPLEMENTAL PACK NR 1 CLOSED AT 25000 FEET CAUSING THE CABIN ALT. TO GO TO RED ON THE EICAS WE FOLLOW THE CHECKLIST, STARTED WORKIN FINE. FEW MINUTES LATER CABIN ALTITUDE STARTED TO INCRESE TO RED ON EICAS. C/A-REMOVED AND REPLACED COUPLING & CLAMPS AFT OF DUAL VALVE TORQUE MOTOR IN NR 1 PACK AREA IAW AMM 21-51-00 OPS CHECK GOOD. REMOVED AND REPLACED RT LINEAR ACTUATOR IAW AMM 21-25-01. PERFORMED OPERATIONAL CHECK IAW AMM 21-25-01. INSTALLED PANEL 191EL IAW AMM 06-41-01