What was found
APPROXIMATELY 2 HRS INTO FLT, NOTICED A FAINT ACRID ODOR WHEN TRING TO CALL F/A. FOUND THE CABIN NOTIFICATION CHIME INOPERATIVE. WORKED NORMALLY PRIOR TO THIS. THEN TRIED PA ALSO INOPERATIVE. ELECTED NOT TO PULL AND RESET CIRCUIT BREAKERS DUE TO ACRID ODOR AT THE TIME OF FAILURE. FOUND PA AMPLIFIER BITE TEST WILL NOT PASS. REPLACED PA AMPLIFIER IAW AMM 23-31 INSTALLATION TEST PASSED IAW FIM 23-31.