Loss of the Weather Radar Information on the ND
TASK 34-41-00-810-801-A
Loss of the Weather Radar Information on the ND
1. Possible Causes
A. Referenced Information
3. Fault Confirmation
Subtask 34-41-00-730-050-A 4. Fault Isolation
Subtask 34-41-00-810-051-A ** ON A/C NOT FOR ALL
[Rev.8 from Aug 2018]
2026.04.04 04:33:04 UTC
Loss of the Weather Radar Information on the ND
1. Possible Causes
- DMC-1 [1WT1]
wiring of the WR1 INPUT 1 and the WR1 INPUT 2 buses from the DMC1 (1WT1) to the first terminal block wiring of the W/R SELECTED discrete from the DMC1 (1WT1) to the first terminal block wiring from the DMC1 (1WT1) to the CAPT ND (3WT1) wiring of the WR1 INPUT 1 and the WR1 INPUT 2 buses from the DMC-1 (1WT1) to the first terminal block wiring from the DMC-1 (1WT1) to the CAPT ND (3WT1) - XCVR-WEATHER RADAR, 1 [1SQ1]
- DMC-2 [1WT2]
wiring of the WR1 INPUT 1 and the WR1 INPUT 2 buses from the DMC2 (1WT2) to the first terminal block wiring of the W/R SELECTED discrete from the DMC2 (1WT2) to the first terminal block wiring from the DMC2 (1WT2) to the F/O ND (3WT2) - avionics ventilation
wiring of the TR1 DATA BUS 1 OUTPUT and the TR1 DATA BUS 2 OUTPUT buses from the weather radar transceiver 1 (1SQ1) to the first terminal block wiring of the weather radar control unit (3SQ) wiring of the weather radar transceiver mounting tray (9SQ) - CTL UNIT-WEATHER RADAR [3SQ]
- MTG TRAY-WR XCVR [9SQ]
- RADOME [1560WM]
A. Referenced Information
| REFERENCE | DESIGNATION |
|---|---|
| ASM 316104 | |
| AMM 31-63-34-000-001 | Removal of the DMC |
| AMM 31-63-34-400-001 | Installation of the DMC |
| AMM 34-41-00-730-001 | System Test of the Weather Radar |
| AMM 34-41-00-740-002 | BITE Test of the Weather Radar |
| ASM 344101 | |
| AMM 34-41-12-000-001 | Removal of the Weather Radar Control Unit |
| AMM 34-41-12-400-001 | Installation of the Weather Radar Control Unit |
| AMM 34-41-33-000-004 | Removal of the Weather Radar Transceiver |
| AMM 34-41-33-000-010 | Removal of the Weather Radar Transceiver |
| AMM 34-41-33-000-802 | Removal of the Weather Radar Transceiver |
| AMM 34-41-33-400-003 | Installation of the Weather Radar Transceiver |
| AMM 34-41-33-400-007 | Installation of the Weather Radar Transceiver |
| AMM 34-41-33-400-802 | Installation of the Weather Radar Transceiver |
| AMM 34-41-37-000-001 | Removal of the Weather Radar Transceiver Mounting Tray |
| AMM 34-41-37-400-001 | Installation of the Weather Radar Transceiver Mounting Tray |
| AMM 53-15-11-000-001 | Removal of the Radome |
| AMM 53-15-11-400-001 | Installation of the Radome |
Subtask 34-41-00-730-050-A 4. Fault Isolation
Subtask 34-41-00-810-051-A ** ON A/C NOT FOR ALL
A. If the weather radar display is not shown or incorrectly shown on the CAPT ND only:
Subtask 34-41-00-810-070-A ** ON A/C NOT FOR ALL - on the center pedestal, on the SWITCHING panel 8VU, set the EIS DMC selector switch to CAPT/3, and make sure that the weather radar display is correctly shown on the CAPT ND.
- replace the DMC-1 [1WT1] AMM 31-63-34-000-001 and AMM 31-63-34-400-001.
- do a check of the
wiring of the WR1 INPUT 1 and the WR1 INPUT 2 buses from the DMC1 (1WT1) to the first terminal block ASM 344101.
- repair the above wiring.
- do a check and repair the
wiring of the W/R SELECTED discrete from the DMC1 (1WT1) to the first terminal block ASM 344101.
- replace the DMC-1 [1WT1] AMM 31-63-34-000-001 and AMM 31-63-34-400-001.
- do a check and repair the
wiring from the DMC1 (1WT1) to the CAPT ND (3WT1) :
. from pins AB/12B, 12C to pins AA/13, 14
. from pins AB/12H, 12J to pins AA/40, 41
. from pins AB/13B, 13C to pins AA/28, 29
. from pins AB/13H, 13J to pins AA/26, 27
ASM 316104.
B. If the weather radar display is not shown or incorrectly shown on the F/O ND only:
Subtask 34-41-00-810-051-E ** ON A/C NOT FOR ALL - on the center pedestal, on the SWITCHING panel 8VU, set the EIS DMC selector switch to F/O/3, and make sure that the weather radar display is correctly shown on the F/O ND.
- replace the DMC-2 [1WT2] AMM 31-63-34-000-001 and AMM 31-63-34-400-001.
- do a check of the
wiring of the WR1 INPUT 1 and the WR1 INPUT 2 buses from the DMC2 (1WT2) to the first terminal block ASM 344101.
- repair the above wiring.
- do a check and repair the
wiring of the W/R SELECTED discrete from the DMC2 (1WT2) to the first terminal block ASM 344101.
- replace the DMC-2 [1WT2] AMM 31-63-34-000-001 and AMM 31-63-34-400-001.
- do a check and repair the
wiring from the DMC2 (1WT2) to the F/O ND (3WT2) :
. from pins AB/12B, 12C to pins AA/13, 14
. from pins AB/12H, 12J to pins AA/40, 41
. from pins AB/13B, 13C to pins AA/28, 29
. from pins AB/13H, 13J to pins AA/26, 27
ASM 316104.
C. If the weather radar display is not shown or incorrectly shown on the CAPT ND only:
Subtask 34-41-00-810-070-E ** ON A/C NOT FOR ALL - check that CAPT TERR ON ND pushbutton (30WZ1) is not pressed (WX data selected for display).
- on the center pedestal, on the SWITCHING panel 8VU, set the EIS DMC selector switch to CAPT/3, and make sure that the weather radar display is correctly shown on the CAPT ND.
- replace the DMC-1 [1WT1] AMM 31-63-34-000-001 and AMM 31-63-34-400-001.
- do a check of the
wiring of the WR1 INPUT 1 and the WR1 INPUT 2 buses from the DMC-1 (1WT1) to the first terminal block ASM 344101.
- repair the above wiring.
- do a check and repair the
wiring from the DMC-1 (1WT1) to the CAPT ND (3WT1) :
. from pin AB/14B to pin AA/1
. from pin AB/14C to pin AA/10
. from pin AB/15B to pin AA/20
ASM 316104.
- replace the XCVR-WEATHER RADAR, 1 [1SQ1] AMM 34-41-33-000-010 and AMM 34-41-33-400-007.
D. If the weather radar display is not shown or incorrectly shown on the F/O ND only:
Subtask 34-41-00-810-071-A - on the center pedestal, on the SWITCHING panel 8VU, set the EIS DMC selector switch to F/O/3, and make sure that the weather radar display is correctly shown on the F/O ND.
- replace the DMC-2 [1WT2] AMM 31-63-34-000-001 and AMM 31-63-34-400-001.
- do a check of the
wiring of the WR1 INPUT 1 and the WR1 INPUT 2 buses from the DMC2 (1WT2) to the first terminal block ASM 344101.
- repair the above wiring.
- do a check and repair the
wiring of the W/R SELECTED discrete from the DMC2 (1WT2) to the first terminal block ASM 344101.
- replace the DMC-2 [1WT2] AMM 31-63-34-000-001 and AMM 31-63-34-400-001.
- do a check and repair the
wiring from the DMC2 (1WT2) to the F/O ND (3WT2) :
. from pin AB/14B to pin AA/1
. from pin AB/14C to pin AA/10
. from pin AB/15B to pin AA/20
ASM 316104.
E. If the weather radar display is not shown or incorrectly shown on the two NDs:
Subtask 34-41-00-730-051-A - do the BITE test of the weather radar AMM 34-41-00-740-002.
NOTE: In case of incorrect avionics ventilation , the radar images are not shown to prevent overheat of NDs.
(1) If the test gives a maintenance message: - do the related trouble shooting procedure(s).
- replace the XCVR-WEATHER RADAR, 1 [1SQ1] AMM 34-41-33-000-004 AMM 34-41-33-000-802 and AMM 34-41-33-400-003 AMM 34-41-33-400-802.
- do a check of the
wiring of the TR1 DATA BUS 1 OUTPUT and the TR1 DATA BUS 2 OUTPUT buses from the weather radar transceiver 1 (1SQ1) to the first terminal block ASM 344101.
- repair the above wiring.
- do a check of the
wiring of the weather radar control unit (3SQ) :
. from pin A/G to the first terminal block
. from pin A/A to the ground point
. from pins A/K, L, M to the weather radar transceiver 1 (1SQ1), pins AB/6C, 6D, 7D
. from pin A/V to the weather radar transceiver 1 (1SQ1), pin AB/6B
ASM 344101.
- repair the above wiring.
- do a check of the
wiring of the weather radar transceiver mounting tray (9SQ) :
. from pins A/A and A/E to the control unit (3SQ), pins A/D and A/E.
. from pin A/F to the ground point.
. from pin A/C to the weather radar transceiver 1 (1SQ1), pin AB/8D.
ASM 344101. - if there is no continuity:
. repair the above wiring. - if there is continuity:
. replace the CTL UNIT-WEATHER RADAR [3SQ] AMM 34-41-12-000-001 and AMM 34-41-12-400-001. - If the fault continues:
. replace the MTG TRAY-WR XCVR [9SQ] AMM 34-41-37-000-001 and AMM 34-41-37-400-001.
- If the radar system trouble shooting is unsatisfactory, replace the RADOME [1560WM] AMM 53-15-11-000-001 and AMM 53-15-11-400-001.
F. Do the test given in Para. 3.