(3)  
Do this check of the ADIRU switching:

(a)  
Make sure the left ADIRU is aligned and in the NAV mode.

(b)  
Set the IRS switch on the P5 panel to the BOTH ON L position.

(c)  
If the observed fault does not show on the first officer’s EFIS display, then do these steps:

1) Replace the right ADIRU. These are the tasks: Air Data Inertial Reference Unit Removal, AMM TASK 34-21-01-000-801, Air Data Inertial Reference Unit Installation, AMM TASK 34-21-01-400-801.

(d)  
If the observed fault shows on the first officer’s EFIS display, then continue.

(4)
Replace the DEU 2. These are the Task: Display Electronic Unit Removal, AMM TASK 31-62-21-000-801, Display Electronic Unit Installation, AMM TASK 31-62-21-400-801.

(a)  If the installation test is satisfactory, then you corrected the fault.

(5)  
Do a wiring check between the ADR to IR section of the ADIRU.

EFFECTIVITY SIL ALL  34-21 TASK 826 
D633A103-SIL BOEING PROPRIETARY -Copyright # Unpublished Work -See title page for details  Page 252 Oct 15/2008 

(a)  For the right ADIRU, do a wiring check between terminal block TB521, to D3693B and D3693A:
TB523  D3687B
ZA21 -------------------pinK4
ZB21 -------------------pinK5

TB523  D3687A
ZA21 -------------------pinA9
ZB21 -------------------pinB9

(b)  If you find a problem with the wiring, then do these steps:
1) Repair the wiring.
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. c) After you clear the left ADIRS maintenance messages, if the observed fault continues to shows on the captain’s EFIS display, then continue.
(c)  If you don’t find the problem with the wiring, then continue.
(6)  Do this check of the wiring between the ADIRUs and the DEU 2:
(a)  
Remove the left and right ADIRUs. To remove them, do this task: Air Data Inertial Reference Unit Removal, AMM TASK 34-21-01-000-801.

(b)  
Remove the DEU 2. To remove it, do this task: Display Electronic Unit Removal, AMM TASK 31-62-21-000-801.

(c)  
For the left ADIRU, do a wiring check between these pins of connectors D3687B and D3975A:

D3687B  D3975A
pinC10 -----------------pinC2 pinC11 -----------------pinD2

(d)  For the right ADIRU, do a wiring check between these pins of connectors D3693B and D3975D:
D3693B  D3975D
pinG7 ------------------pinC2 pinG8 ------------------pinD2

(e)  If you find a problem with the wiring, then do these steps:
1) Repair the wiring.

EFFECTIVITY SIL ALL  34-21 TASK 826 
D633A103-SIL BOEING PROPRIETARY -Copyright # Unpublished Work -See title page for details  Page 253 Oct 15/2008 

3)  Re-install the left and right ADIRUs. To install them, do this task: Air Data Inertial Reference Unit Installation, AMM TASK 34-21-01-400-801.
4)  If the observed fault does not show on the first officer’s EFIS display, then you corrected the fault.
-------------------------END OF TASK ---------------------------
827. ADR Observed Faults on Captain’s EFIS Displays -Fault Isolation
A.  Description
(1) This task is for these observed faults:
(a)
ALT flag shows on the captain’s EFIS display.

(b)
SPD flag shows on captain’s EFIS display.
　
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