04/26/21
Message Overview:
Message Description:
The green light above the Comm #1 selection on Audio Control Panel #2 is flashing on and off.
Possible Causes:
- L Control Panel Electronics (CPE 1) (A167)
- R Control Panel Electronics (CPE 2) (A168)
- Junction Box 2 (JB2)
- Junction Box 3 (JB3)
- L Radio Interface Unit (RIU 1) (A17)
- R Radio Interface Unit (RIU 1) (A18)
- L Audio Control Panel (ACP 1) (PL1)
- R Audio Control Panel (ACP 2) (PL2)
- Associated Wiring
Troubleshooting Tips:
Advisory Wire/Service Bulletin: None
Forum Articles/Infoservice/Newsletter: None
Quick Links:
| Removal of the Audio Control Panel | AMM 23-51-05-000-801 |
| Installation of the Audio Control Panel | AMM 23-51-05-400-801 |
| Removal of the Control Panel Electronic (CPE) | AMM 23-51-09-000-801 |
| Installation of the Control Panel Electronic (CPE) | AMM 23-51-09-400-801 |
| Removal of the Secondary Power Center (SPC) | AMM 24-62-01-000-801 |
| Installation of the Secondary Power Center (SPC) | AMM 24-62-01-400-801 |
| Removal of the Junction Box JB2 | AMM 24-63-05-000-803 |
| Installation of the Junction Box JB2 | AMM 24-63-05-400-803 |
| Removal of the Junction Box JB3 | AMM 24-63-09-000-802 |
| Installation of the Junction Box JB3 | AMM 24-63-09-400-802 |
| Removal of the Cockpit Circuit-Breaker Panel (CCBP) | AMM 24-65-01-000-801 |
| Installation of the Cockpit Circuit-Breaker Panel (CCBP) | AMM 24-65-01-400-801 |
| Standard Practices - Replace Wiring | SPM 20-12-00-02 |
| Standard Practices - Repair Wiring | SPM 20-12-10-02 |
Troubleshooting Recommendations:
- Simultaneously reset L AUDIO PWR 1 Circuit Breaker CB1-B1 and L AUDIO PWR 2 Circuit Breaker CB4-F4 AND R AUDIO PWR 1 Circuit Breaker CB2-B1 and R AUDIO PWR 2 Circuit Breaker CB3-F4. Is the fault message still present?
- If YES, continue with next step.
- If NO, do close out.
- Swap Left CPE (167) with right CPE (A168). Is the fault message still present?
- If YES, continue with next step.
- If NO, replace defective CPE.
- Do wiring check between the Left CPE (A167) and the Junction Box 3 (JB3) for the following wires:
From To Result Conn. A167P1 - 3 Aircraft Ground Conn. A167P1 - 8 Aircraft Ground Conn. A167P1 - 1 Conn. JB3BP1 - 46 - If the check is satisfactory, go to next step.
- If the check is not satisfactory, repair defective wiring or replace JB3.
- Do wiring check between the right CPE (A168) and the Junction Box 2 (JB2) for the following wires:
From To Result Conn. A168P1 - 3 Aircraft Ground Conn. A168P1 - 8 Aircraft Ground Conn. A168P1 - 1 Conn. JB2BP1 - 10H - If the check is satisfactory, go to next step.
- If the check is not satisfactory, repair defective wiring or replace JB2.
- Do wiring check between the Junction Box 3 (JB3), the Circuit Breaker Panel 1, the Right Secondary Power Center (A38) and the left Audio Control Panel (PL1) for the following wires:
From To Result Note Conn. JB3BP1 - 48 Conn. A38P3 - 18 Respect diode CR45 polarity Conn. JB3BP1 - 45 Conn. CBP1J1 - 34 Respect diode CR46 polarity Conn. JB3BP1 - 47 Conn. PL1P1 - A - If the check is satisfactory, go to next step.
- If the check is not satisfactory, repair defective wiring.
NOTE: A short circuit on one of these wire or internally to the Audio Control Panel 1 will cause this fault message.
- Replace the left Audio Control Panel (PL1).
- Do wiring check between the Junction Box 2 (JB2), the Circuit Breaker Panel 2, the left Secondary Power Center (A37) and the right Audio Control Panel (PL2) for the following wires:
From To Result Note Conn. JB2AP1 - 6A Conn. A37P3 - 18 Respect diode CR47 polarity Conn. JB2AP1 - 10K Conn. CBP2J3 - 11 Respect diode CR47 polarity Conn. JB2AP1 - 10J Conn. PL2P1 - A - If the check is satisfactory, go to next step.
- If the check is not satisfactory, repair defective wiring.
NOTE: A short circuit on one of these wire or internally to the Audio Control Panel 2 will cause this fault message.
- Replace the right Audio Control Panel (PL2).
- Do close out.