D.  Related Data
(1)
(SSM 34-31-11).

(2)
(WDM 34-31-11).

E.  Initial Evaluation
(1)  Do
this
task:
ILS
or
Multi-Mode
Receiver
BITE
Procedure,
34-31
TASK
801.

(a)  
If the flags show on the captain’s display, then do the Fault Isolation below.

(b)  
If the flags do not show on the captain’s display, then there was an intermittent fault.

F.  Fault Isolation Procedure
(1)  
Do this task: Instrument Landing System -Operational Test, AMM TASK 34-31-00-710-801.

(a)  
If the flags show on the captain’s and F/O’s displays while the VHF NAV switch is in the BOTH ON 1 position, then do these steps: 1) Replace the MMR-1, M2104. These are the tasks: Receiver for ILS -Removal, AMM TASK 34-31-42-000-801, Receiver for ILS -Installation, AMM TASK 34-31-42-400-801.

2)  If the flags do not show on the captain’s and F/O’s displays, then you corrected the fault.

(b)  
If the flags show on just the captain’s or F/O’s displays, then do these steps: 1) Replace the VHF NAV switch S2, P5-28. 2) If the flags does not show on the captain’s and F/O’s displays, then you corrected the

fault. 3) If the flags show on the captain’s or F/O’s displays, then continue.

(c)  
If the flags only show on the captain’s display while the VHF NAV switch is in the BOTH ON 1 position, then continue.

(2)  
Do this check of the wiring between the VHF NAV switch and the DEU, M1808:

EFFECTIVITY SIL ALL  34-31 TASK 806 
D633A103-SIL BOEING PROPRIETARY -Copyright # Unpublished Work -See title page for details  Page 206 Oct 10/2006 

(a)  
Set the VHF NAV switch to the BOTH ON 1 position.

(b)  
Remove the DEU, M1808. To remove it, do this task: Display Electronic Unit Removal, AMM TASK 31-62-21-000-801.

(c)  
Do a continuity check between pin G10 of the connector D3973E and structure ground

(d)  
If there is not continuity between pin G10 and structure ground, then do these steps: 1) Repair the wiring. 2) Re-install the DEU, M1808. To install it, do this task: Display Electronic Unit

Installation, AMM TASK 31-62-21-400-801. 3) If the flags does not show on the F/O’s display, then you corrected the fault.

(e)  
If there is continuity between pin G10 and structure ground, then continue.

SIL ALL; AIRPLANES WITH MULTI-MODE RECEIVERS (MMR)
(3) Do this check of the wiring between the DEU and the MMR:
(a)  
Remove the DEU, M1808. To remove it, do this task: Display Electronic Unit Removal, AMM TASK 31-62-21-000-801.

(b)  
Remove the MMR-1, M2104. To remove it, do this task: Receiver for ILS -Removal, AMM TASK 34-31-42-000-801.

(c)  
Do a check for an open circuit between the pins specified for the applicable fault flag:

DEU  MMR 
CONNECTOR  CONNECTOR 
LOC FLAG  D3973A  D10719B 
pin C15  ----------------- pin G1 
pin D15  ----------------- pin H1 
G/S FLAG  D3973E  D10719B 
pin G3  ------------------ pin G1 
pin H3  ------------------ pin H1 
(d)  If there is an open circuit,  then do these steps: 
1) Repair the wiring. 

2)  Re-install the MMR-1, M2104. To install it, do this task: Receiver for ILS -Installation, AMM TASK 34-31-42-400-801.
3)  Re-install the DEU, M1808. To install it, do this task: Display Electronic Unit Installation, AMM TASK 31-62-21-400-801.
　
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