External Power not Available although the External Power Energizes the Aircraft

TASK 24-40-00-810-812-A
External Power not Available although the External Power Energizes the Aircraft

1. Possible Causes

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
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
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)

3. Fault Confirmation
Subtask 24-40-00-710-062-A

A. Test
(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 stays off and the EXT PWR/AVAIL caution light stays off
on the ELEC panel 35VU: the AVAIL legend of the EXT PWR pushbutton switch stays off.

4. Fault Isolation
Subtask 24-40-00-810-061-A ** ON A/C NOT FOR ALL

A. If the test confirms the fault:

Subtask 24-40-00-810-061-B ** ON A/C NOT FOR ALL

A. If the test confirms the fault:

Subtask 24-40-00-710-063-A

B. Do this test to make sure that the system operates correctly:
(1) Do the 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 ELEC panel 35VU, the AVAIL legend of the EXT PWR pushbutton switch comes on.

(2) De-energize the aircraft electrical circuits from the external power AMM 24-41-00-862-002.

[Rev.8 from Aug 2018] 2026.04.04 04:26:53 UTC