Message Name:

NO OUTPUT

Message Code:

B3-006487

Associated CAS:

None

No A-DCU data received at L-IOC AND 2 of (L-PFD, L-MFD, R-PFD, R-MFD) and 3 of (ASC1A, IASC1B, IASC2A, IASC2B, LDU, L-RIU).

• Data Concentrator Unit (DCU) (A14)
• EICAS DCU A Circuit Breaker (CB1-D1)
• Left Cockpit Circuit-Breaker Panel (LCBP) (CBP1)
• Junction Box 2 (JB2)
• Associated Wiring

Advisory Wire/Service Bulletin: None

Forum Articles/Infoservice/Newsletter: None

1. Reset EICAS DCU A Circuit Breaker CB1-D1. Is the fault message still present?

1. If NO, do close out.
2. If YES, continue with next step.

2. Confirm presence of the Ground at the DCU (A14).

   Measurement at	Expected Result	Result
   Conn. A14CP1 - 2A	Aircraft Ground (PWR GND)
   Conn. A14CP1 - 2B	Aircraft Ground (PWR GND)
   Conn. A14CP1 - 7C	Aircraft Ground (Chassis GND)
   Conn. A14CP1 - 7D	Aircraft Ground (Chassis GND)
   Conn. A14CP1 - 7G	Aircraft Ground (Chassis GND)
   Conn. A14CP1 - 7H	Aircraft Ground (Chassis GND)

1. If the check is satisfactory, continue with next step.
2. If the check is not satisfactory, repair wiring.

3. Confirm presence of the 28 VDC at the DCU (A14).

   Measurement at	Expected Result	Result
   Conn. A14CP1 - 1A	Aircraft Ground (PWR GND)
   Conn. A14CP1 - 1B	Aircraft Ground (PWR GND)

   1. If the check is satisfactory, continue with step 6.
   2. If the check is not satisfactory, continue with next step.

4. Do wiring check between DCU (A14) and left Circuit Breaker Panel (CBP1), through Junction Box 2 for the following wires:

   From	To	Result
   Conn. A14CP1 - 1A	CBP1J1 - 42
   Conn. A14CP1 - 1B	CBP1J1 - 42

   1. If the check is satisfactory, continue with next step.
   2. If the check is not satisfactory, repair defective wire or Junction Box 2.

5. Replace EICAS DCU A Circuit Breaker CB1-D1. Is the fault message still present\?

   1. If NO, do close out.
   2. If YES, replace defective Circuit Breaker Panel.

6. Replace DCU (A14).
7. Do close out.