DOC AIRBUS | TSM A320FThe AVAIL Legend of the ELEC/EXT PWR Pushbutton Switch Does not Come on when the EXT PWR is Available but not Used
TASK 24-40-00-810-806-A
The AVAIL Legend of the ELEC/EXT PWR Pushbutton Switch Does not Come on when the EXT PWR is Available but not Used
1. Possible Causes
A. Referenced Information
3. Fault Confirmation
Subtask 24-40-00-710-050-A
Subtask 24-40-00-810-055-A ** ON A/C NOT FOR ALL
[Rev.8 from Aug 2018]
2026.04.04 04:26:52 UTC
The AVAIL Legend of the ELEC/EXT PWR Pushbutton Switch Does not Come on when the EXT PWR is Available but not Used
1. Possible Causes
- BOARD-ANN LT TEST & INTFC [10LP]
- 22XU1
- RELAY [21XG]
- wiring
- lamp
- P/BSW-ELEC/EXT PWR [10XG]
- GAPCU [24XG]
A. Referenced Information
| REFERENCE | DESIGNATION |
|---|---|
| AMM 24-22-33-000-001 | Removal of the EGIU-1(2) |
| AMM 24-22-33-400-002 | Installation of the EGIU-1(2) |
| AMM 24-41-00-861-002 | Energize the Aircraft Electrical Circuits from the External Power |
| AMM 24-41-00-862-002 | De-energize the Aircraft Electrical Circuits Supplied from the External Power |
| ASM 244101 | |
| AMM 24-41-34-000-001 | Removal of the Ground Power Control Unit (GPCU) |
| AMM 24-41-34-400-001 | Installation of the Ground Power Control Unit (GPCU) |
| AMM 33-14-00-710-001 | Operational Test of the Lights |
| AMM 33-14-33-000-001 | Removal of the Annunciator-Light Test and Interface-Board |
| AMM 33-14-33-400-001 | Installation of the Annunciator-Light Test and Interface-Board |
Subtask 24-40-00-710-050-A
A. Test
(1) Energize the aircraft electrical circuits from the external power AMM 24-41-00-861-002.
4. Fault Isolation(1) Energize the aircraft electrical circuits from the external power AMM 24-41-00-861-002.
NOTE: Energization of the aircraft is correct but, during the procedure given at Para. 3.D., make sure that:
- on the panel 108VU : the EXT PWR/NOT IN USE indicator light and the EXT PWR/AVAIL caution light come on.
- on the panel 35VU : the AVAIL legend of the EXT PWR pushbutton switch stays off AMM 33-14-00-710-001.
Subtask 24-40-00-810-055-A ** ON A/C NOT FOR ALL
A. If the test confirms the fault:
Subtask 24-40-00-810-055-B ** ON A/C NOT FOR ALL - do the operational test of the annunciator light test system AMM 33-14-00-710-001.
- replace the BOARD-ANN LT TEST & INTFC [10LP] AMM 33-14-33-000-001 and AMM 33-14-33-400-001.
- replace the 22XU1 AMM 24-22-33-000-001 and AMM 24-22-33-400-002.
- replace the RELAY [21XG] .
- do a check and repair the wiring from the EGIU1 (22XU1) to the relay (21XG) ASM 244101.
- Replace the lamp of the AVAIL legend of the ELEC/EXT PWR pushbutton switch, if the ELEC/EXT PWR pushbutton switch is fitted with lamps, or
- Replace the P/BSW-ELEC/EXT PWR [10XG] , if the ELEC/EXT PWR pushbutton switch is fitted with LED.
- replace the P/BSW-ELEC/EXT PWR [10XG] .
- replace the BOARD-ANN LT TEST & INTFC [10LP] AMM 33-14-33-000-001 and AMM 33-14-33-400-001.
- do a check and repair the wiring
. between the pin A/7 of the ELEC/EXT PWR pushbutton switch and the relay (21XG) pin A/A2.
. between the pin A/8 of the ELEC/EXT PWR pushbutton switch and the pin A/10 of the ANN LT TEST & INTFC board ASM 244101.
A. If the test confirms the fault:
Subtask 24-40-00-710-051-A - do the operational test of the annunciator-light test system AMM 33-14-00-710-001.
- replace the BOARD-ANN LT TEST & INTFC [10LP] AMM 33-14-33-000-001 and AMM 33-14-33-400-001.
- replace the GAPCU [24XG] AMM 24-41-34-000-001 and AMM 24-41-34-400-001.
- replace the RELAY [21XG] .
- do a check and repair the wiring between the pin AB/3C of the GAPCU (24XG) and the pin A/A3 of the relay (21XG) ASM 244101.
- replace the lamp of the AVAIL legend of the ELEC/EXT PWR pushbutton switch, if the ELEC/EXT PWR pushbutton switch is fitted with lamps, or
- replace the P/BSW-ELEC/EXT PWR [10XG] , if the ELEC/EXT PWR pushbutton switch is fitted with LED.
- replace the P/BSW-ELEC/EXT PWR [10XG] .
- replace the BOARD-ANN LT TEST & INTFC [10LP] AMM 33-14-33-000-001 and AMM 33-14-33-400-001.
- do a check and repair the wiring between:
. the pin A/7 of the ELEC/EXT PWR pushbutton switch and the pin A/A2 of the relay (21XG)
. the pin A/8 of the ELEC/EXT PWR pushbutton switch and the pin A/10 of the ANN LT TEST & INTFC board ASM 244101.
B. Do this test to make sure that the system operates correctly.
(1) Do this test given in Para. 3. and make sure that:
(1) Do this test given in Para. 3. and make sure that:
- on the panel 108VU, the EXT PWR/NOT IN USE indicator light and EXT PWR/AVAIL caution light come on.
- on the panel 35VU, the AVAIL legend of the EXT PWR pushbutton switch comes on.