Failure of the Avionics Compartment Dome Lights

TASK 33-35-00-810-802-A
Failure of the Avionics Compartment Dome Lights

1. Possible Causes

P/BSW-AVIONICS COMPT LT (23LS)
wiring
C/B-LIGHTING/AVNCS COMPT/DOME [1LS]

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
TSM TASK 24-00-00-810-803-A	Circuit Breaker Tripped and/or C/B TRIPPED Warning
AMM 33-35-00-720-001	Functional Test of the Avionics-Compartment Lighting
ASM 333501
AIPC 333508

3. Fault Confirmation
Subtask 33-35-00-720-052-A

A. Test
Do the functional test of the equipment compartment lighting AMM 33-35-00-720-001.

4. Fault Isolation
Subtask 33-35-00-810-051-A

A. If, during the functional test, when you push the avionics-compartment light pushbutton-switch (23LS), the integral lighting system is inoperative:

do a check of the circuit breaker (1LS) status:

(1) If the circuit breaker is closed:

do a check for 28VDC at pins A/B3, C3 of the pushbutton switch (23LS) ASM 333501.

(a) If there is 28VDC:

replace the P/BSW-AVIONICS COMPT LT (23LS) AIPC 333508.

1 If the fault continues:

do a check and repair the wiring between the pins A/A2, B2 of the power supply relays (24LS) and (25LS) and the circuit breaker (1LS).

(b) If there is no 28VDC:

do a check for 28VDC at pins A/A2, B2 of the power supply relays (24LS) and (25LS).

1 If there is 28VDC:

do a check and repair the wiring between the pins A/B3, C3 and the circuit breaker (1LS).

2 If there is no 28VDC:

replace the C/B-LIGHTING/AVNCS COMPT/DOME [1LS] .

(2) If the circuit breaker is open:

Do the procedure (Ref. TSM TASK 24-00-00-810-803).

(a) If the fault continues:

Replace the C/B-LIGHTING/AVNCS COMPT/DOME [1LS] .

Subtask 33-35-00-720-053-A

B. Do the test given in Para. 3.

[Rev.8 from Aug 2018] 2026.04.04 04:31:56 UTC