Logo Lights - One Logo Light does not come on

TASK 33-47-00-810-801-A
Logo Lights - One Logo Light does not come on

1. Possible Causes

LOGO LIGHT [3LY]
BEAM LAMP
wiring
RELAY 5LY
CB 2LY
LOGO LIGHT [4LY]
CB 1LY

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 33-47-00-710-002	Operational Test of the Logo Lights
ASM 334701
AMM 33-47-11-000-002	Removal of the Logo Light
AMM 33-47-11-400-002	Installation of the Logo Light
AMM 33-47-11-600-001	Replacement of the Lamp of the Logo Light

3. Fault Confirmation
Subtask 33-47-00-710-050-A

A. Do the operational test of the logo lights AMM 33-47-00-710-002.

4. Fault Isolation
Subtask 33-47-00-810-050-A

A. If the test shows that the Logo light (3LY) does not come on:

Make sure that the NAV LOGO switch is set to the ON position,
Do a check for 115VAC at pin A/A of the Logo light (3LY) ASM 334701.

(1) If there is approximately 115VAC:
(a) For GLS LEDs Light Unit technology:
- Replace LOGO LIGHT [3LY] AMM 33-47-11-000-002 and AMM 33-47-11-400-002.
(b) For GLS filament Light technology:

Replace the BEAM LAMP AMM 33-47-11-600-001.

1 If the fault continues:

Replace LOGO LIGHT [3LY] AMM 33-47-11-000-002 and AMM 33-47-11-400-002.

a If the fault continues:

Do a check of the wiring between pin A/B of the Logo light (3LY) and the ground terminal. ASM 334701.

(2) If there is no 115VAC:

Do a check of the wiring between pin A/A of the Logo ligth (3LY) and the Left logo-lighting circuit-breaker (2LY) ASM 334701.

(a) If the fault continues:

Do a check and replace if necessary:
RELAY 5LY
CB 2LY
ASM 334701.

Subtask 33-47-00-810-054-A

B. If the test shows that the Logo light (4LY) does not come on:

Make sure that the NAV LOGO switch is set to the ON position,
Do a check for 115VAC at pin A/A of the Logo light (4LY) ASM 334701.

(1) If there is approx. 115VAC:
(a) For GLS LEDs Light Unit technology:
- Replace LOGO LIGHT [4LY] AMM 33-47-11-000-002 and AMM 33-47-11-400-002.
(b) For GLS filament Light technology:

Replace the BEAM LAMP AMM 33-47-11-600-001.

1 If the fault continues:

Replace LOGO LIGHT [4LY] AMM 33-47-11-000-002 and AMM 33-47-11-400-002.

a If the fault continues:

Do a check of the wiring between pin A/B of the Logo light (4LY) and the ground terminal ASM 334701.

(2) If there is no 115VAC:

Do a check of the wiring between pin A/A of the Logo light (4LY) and the Right logo-lighting circuit-breaker (1LY) ASM 334701.

(a) If the fault continues:

Do a check and replace if necessary:
RELAY 5LY
CB 1LY
ASM 334701.

Subtask 33-47-00-710-051-A

C. Do the test as given in the Para. 3. A.

5. Close-up
Subtask 33-47-00-860-050-A

A. Put the aircraft back to its initial configuration.

[Rev.8 from Aug 2018] 2026.04.04 04:40:21 UTC