7) If the maintenance messages does not show on the CDU and the status code does not show on the ISDU, then you corrected the fault.
-------------------------END OF TASK ---------------------------
825. IR Observed Faults on Captain’s EFIS Displays -Fault Isolation
A. Description
(1) This task is for these observed faults:
(a)
HDG flag shows on the captain’s electronic flight instrument system (EFIS) display.
(b)
TRK flag shows on the captain’s EFIS display.
(c)
Heading or track data does not show on captain’s EFIS display.
(d)
PITCH message shows on the captain’s EFIS display.
(e)
ROLL message shows on the captain’s EFIS display.
(f)
Vertical speed pointer removed from view on the captain’s EFIS display.
(g)
ATT flag shows on captain’s EFIS display.
(h)
VSI flag shows on captain’s EFIS display.
B. Possible Causes
(1)
Left ADIRU, M1749
(2)
DEU 1, M1808
(3)
Wiring between ADR to IR
(4)
Wiring between the ADIRUs and the DEU 1
C. Circuit Breakers
(1) These are the primary circuit breakers related to the fault:
CAPT Electrical System Panel, P18-1
Row Col Number Name
E 5 C01009 ADIRU LEFT DC
E 7 C01007 ADIRU LEFT AC
CAPT Electrical System Panel, P18-2
Row Col Number Name
D 5 C01359 DISPLAY DEU 1 PRI
E 8 C00425 ADIRU LEFT EXC
EFFECTIVITY
34-21 TASKS 824-825
SIL ALL
Page 248 D633A103-SIL Oct 15/2008
F/O Electrical System Panel, P6-1
Row Col Number Name
C 14 C01008 ADIRU RIGHT AC
C 15 C00426 ADIRU RIGHT EXC
C 17 C01010 ADIRU RIGHT DC
D 10 C01361 DISPLAY DEU 1 HOLDUP
D. Related Data
(1)
(SSM 34-21-11)
(2)
(WDM 34-21-11)
(3)
(WDM 31-62-11)
E. Initial Evaluation
(1)
Do these steps to prepare for initial evaluation and fault isolation:
(a)
Make sure the DISPLAY switch on the P5 panel is in the AUTO position.
(b)
Make sure the IRS switch on the P5 panel is in the NORMAL position.
(c)
Make sure the left ADIRU is aligned and in the NAV mode.
(2)
If the observed fault shows on the captain’s EFIS display, then do the Fault Isolation Procedure below.
(3)
If the observed fault does not show on the captain’s EFIS display, then there was an intermittent fault.
F. Fault Isolation Procedure
(1) Do
the
DEU
1
BITE
(31-62
TASK
801).
(a) If there is a maintenance message that relates to the DEU 1 internal fault, the captain’s EFIS display, or the left ADIRU, then go to the applicable fault isolation task for that message to correct the fault.
1) If the observed fault does not show on the captain’s EFIS display, then you corrected the fault.
2) If the observed fault shows on the captain’s EFIS display, then continue.
(2)
Do
the
left
ADIRS
BITE
(34-21
TASK
801).
(a)
If there is a left ADIRS fault message that shows on the CDU, then go to the FIM task to clear that message.
(b)
After you clear the left ADIRS maintenance messages, if the observed fault does not show on the captain’s EFIS display, then you corrected the fault.
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