Loss of the Second and Fourth Rows of the Legend of the ENG 2 FIRE Pushbutton Switch

TASK 26-12-00-810-816-A
Loss of the Second and Fourth Rows of the Legend of the ENG 2 FIRE Pushbutton Switch

1. Possible Causes

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 26-12-00-710-001	Operational Check of Loop/Squib
ASM 261201
AMM 26-12-12-000-001	Removal of the ENG/APU Fire Panel
AMM 26-12-12-400-001	Installation of the ENG/APU Fire Panel
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 26-12-00-865-053-A

A. Make sure that this(these) circuit breaker(s) is(are) closed:

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
122VU	LIGHTING/TST/BOARD/SPLY	30LP	X06

Subtask 26-12-00-710-078-A

B. Test
(1) Do the operational test of the engine fire and overheat detection (loop/squib) AMM 26-12-00-710-001.

4. Fault Isolation
Subtask 26-12-00-810-065-A

A. If during the test, the second and fourth rows of the legend of the ENG 2 FIRE pushbutton switch do not come on:

on the panel 25VU, set the ANN LT switch to TEST and do a check to see if the second and fourth rows of the legend of the ENG 2 FIRE pushbutton switch come on.

(1) If they come on:

replace the BOARD-ANN LT TEST & INTFC [5LP] AMM 33-14-33-000-001 and AMM 33-14-33-400-001.

(a) If the fault continues:

do a check and repair the wiring of the annunciator light test and interface board (5LP) from pin A/34 to the first terminal block and from pin A/35 to pin A/21 ASM 261201.

(b) If they do not come on:

1 If the fault continues:

do a check and repair the wiring of the ENG/APU fire panel (1WD) from pin D/A to the first terminal block and from pin D/B to the pin A/18 of the annunciator light test and interface board (5LP) ASM 261201.

Subtask 26-12-00-710-079-A

B. Do the test given in Para. 3.

5. Close-up
Subtask 26-12-00-860-053-A

A. Put the aircraft back to its initial configuration.
(1) On the panel 25VU, set the ANN LT switch to BRT.

[Rev.8 from Aug 2018] 2026.04.04 04:27:09 UTC