FAULT Light of the PTU P/BSW is ON

TASK 29-23-00-810-808-A
FAULT Light of the PTU P/BSW is ON

1. Possible Causes

BOARD-ANN LT TEST & INTFC [20LP]
wiring

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 33-14-00-710-001	Operational Test of the Lights
ASM 331422
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

3. Fault Confirmation
Subtask 29-23-00-860-052-A

A. Aircraft Maintenance Configuration
(1) Energize the aircraft electrical circuits
AMM 24-41-00-861-002.
(2) On the overhead panel 40VU, look for the FAULT light of the PTU P/BSW.

4. Fault Isolation
Subtask 29-23-00-810-060-A

A. If the Fault Confirmation gives:

the PTU P/BSW FAULT on panel 40VU:
replace the BOARD-ANN LT TEST & INTFC [20LP] AMM 33-14-33-000-001 and AMM 33-14-33-400-001.

(1) If the fault continues:

do a check and repair the wiring between the:
BOARD-ANN LT TEST & INTFC (20LP) pin A/37 and the P/BSW-HYD/PTU (1802GL) pin A/7 ASM 331422.

Subtask 29-23-00-710-064-A

B. Do the operational test of the annunciator light test system AMM 33-14-00-710-001 to make sure that the operation is correct.

5. Close-up
Subtask 29-23-00-860-053-A

A. De-energize the aircraft electrical circuits
AMM 24-41-00-862-002.

[Rev.8 from Aug 2018] 2026.04.04 04:29:29 UTC