- Comman Display System Faults:
INSTR Switch Message:
1.Inertial reference data from the same source. Check the overhead IRS switch, make sure its in the normal position.
CDS Maint Message:1.Message displayed only on the ground, prior to second engine start.
2.Partial DEU failure.
CDS Fault Message:1.Message displayed on ground (Inhibited after second engine start).
2.DEU failure or both DEU(S) have a partial failure.
3.Incompatible S/W or H/W.
4.Miscompare of critical data.
5.Hot battery bus not available.
6.Data load switch in DEU 1 or DEU 2 position. (shows on the ground with at least one engine shut off) for hot hot battery bus or data load switch, CDS fault is removed when both engines start.
7.HYD pressure "A" missing = DEU1. HYD pressure "B" missing = DEU2.
CDS Source Message:1.Message is displayed in the air.
2.Message is displayed on the ground only when both engines are running. On ground after engines are off, CDS Fault message replaces the DSPLY Source message.
3.Also, shows when all on 1 (2) is selected on overhead display source switch.
Display Control Panel:1.ON-SIDE EFIS control panel failure. The altimeter indicator also flags with an ALT flag, because the ON-Side ADIRU loses BARO correction from the EFIS control panel.
Test:1. Perform test from MCDU (Maint/CDS/DEU 1 or 2/ Current status).
CDS Messages:
Circuit Breakers:DEU#1 HOLD UP: P6-1 = D10.
DEU#1 PRIMARY: P18-2 = D5.
DEU#2 HOLD UP: P6-1 = D9.
DEU#2 PRIMARY: P6-1 = D11.
CAPT EFIS Control Panel: P18-2 = D1.
FO's EFIS Control Panel: P6-1 = E13.
Applicable deferrals MEL 34-32 = Instrument Transfer Switching System
MEL 31-8 = CDS MAINT Annunciation
MEL 34-48 = EFIS Control Panel Map Switches