Message Name:

NO OUTPUT

Message Code:

B3-007546

Associated CAS:

None

Right IOC is reporting power failure for the Left IOC and 3 of the following LRUs are reporting a bus failure for the Left IOC (PFD 2, ADC 1, CDU 2, FMC 2, DCU 1, DCU 2, MFD 2, FGC 1).

• Left Integrated-Avionics Processor System (IAPS) Power Supply 1 (PWR) (A4-PWR)
• Integrated-Avionics Processor System (IAPS) Card Cage (ICC) (A4)
• Associated Wiring

Advisory Wire/Service Bulletin: None

Forum Articles/Infoservice/Newsletter: None

1. Reset L IAPS Circuit Breaker CB1-B6, R IAPS Circuit Breaker CB2-B6. Is the fault message still present?

   1. If YES, continue with next step.
   2. If NO, do close out.
      NOTE: Before you open the IAPS circuit breakers, make sure that all Engine FADEC circuit breakers are open. If the Engine FADEC circuit breakers remain closed, Engine Igniters will activate. This can cause injury to persons and damage to equipment.

2. With a multi-meter, verify presence of 28 VDC and GND for the IAPS PWR at the IAPS Card Cage (A4).

   From	To	Expected Result	Result
   Conn. A4P4 - H	Aircraft Ground	28 VDC
   Conn. A4P4 - J	Aircraft Ground	Approx. 0 Ω
   Conn. A4P2 - 21	Aircraft Ground	Approx. 0 Ω
   Conn. A4P2 - 26	Aircraft Ground	Approx. 0 Ω

1. If verification is satisfactory, continue with next step.
2. If verification is not satisfactory, repair/replace defective component.

3. Swap left IAPS PWR with right IAPS PWR. Is the fault message still present?

   1. If YES, continue with next step.
   2. If NO, replace defective IAPS PWR.

4. Replace IAPS card cage (A4).
5. Do close out.