What was found
DURING CRUISE RED MWS, CABIN LIGHT & AUDIBLE CAME ON. CABIN CLIMBING AT 500 TO 700 FT PM. FOLLOWED EMERGENCY CHECKLIST, EXECUTED RAPID DESCENT & DIVERTED. DUMP VALVE PRESSED. WHILE PERFORMING OPS TEST OF CABIN PRESSURE SYS IAW MM 21-32-00, FOUND THAT NEW PAX CONTROLLER WOULD NOT PRESSURIZE CABIN IN AUTO MODE & WHILE SWITCHING FROM MANUAL TO AUTO MODE, AFTER 30 SEC WAIT, RED CABIN ANNUNCIATOR, RED MSW, YELLOW MSC & AUDIBLE CABIN CAME ON & WOULD NOT GO OUT UNTIL SWITCHING BACK TO MANUAL MODE. CABIN CONTROLLER WAS DISPLAYING FAULT CODE A017, INTERNAL ANALOG AMP FAILURE. R & R THE CONTROLLER IAW MM TASK 21-30-01-900-801. OPS TESTED CABIN PRESSURE SYS IAW MM 21-32-00. OPS CHECKED GOOD.