Loss of the FO PFD DU or no variation of Luminosity on the FO PFD DU

TASK 31-63-00-810-978-A
Loss of the FO PFD DU or no variation of Luminosity on the FO PFD DU

1. Possible Causes

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 31-60-00-740-004	EIS System Test
AMM 31-63-22-000-001	Removal of the Display Unit
AMM 31-63-22-400-001	Installation of the Display Unit
AMM 31-63-34-000-001	Removal of the DMC
AMM 31-63-34-400-001	Installation of the DMC
ASM 316801

3. Fault Confirmation
Subtask 31-63-00-740-356-A ** ON A/C NOT FOR ALL

A. Test
Do the EIS system test AMM 31-60-00-740-004.

4. Fault Isolation
Subtask 31-63-00-810-231-A ** ON A/C NOT FOR ALL

A. If the test gives the maintenance message DU PFD FO(2WT2)/PFD FO POT(7WT2):
(1) If there is no FO PFD image:

on the panel 500VU, make sure that the FO PFD potentiometer (7WT2) is in the center position
replace the PFD-F/O [2WT2] , AMM 31-63-22-000-001 and AMM 31-63-22-400-001

(a) If the fault continues:

remove the panel 500VU
on the panel 500VU, do a continuity check between the pins R and W of the connector 2104VC-A

1 If there is continuity:

2 If there is no continuity:

remove the DMC-1 [1WT1] ,
remove the DMC-2 [1WT2]
remove the DMC-3 [1WT3] AMM 31-63-34-000-001
remove the PFD-F/O [2WT2] AMM 31-63-22-000-001
check the wiring between the related LRU and the first terminal block ASM 316801
install the DMC-1 [1WT1] ,
install the DMC-2 [1WT2]
install the DMC-3 [1WT3] AMM 31-63-34-400-001
install the PFD-F/O [2WT2] AMM 31-63-22-400-001
install the panel 500VU

(2) If there is no variation of luminosity on FO PFD DU with the FO PFD potentiometer (7WT2) on the brightness position:

remove the PFD-F/O [2WT2] AMM 31-63-22-000-001
check the wiring between the FO PFD DU (2WT2) and the FO PFD potentiometer (7WT2) ASM 316801
install the FO PFD DU (2WT2) AMM 31-63-22-400-001

5. Close-up
Subtask 31-63-00-740-357-A ** ON A/C NOT FOR ALL

A. Do the test given in Para. 3.A.

[Rev.8 from Aug 2018] 2026.04.04 04:30:50 UTC