Loss of the CVR Recording Logic relays

TASK 23-71-00-810-807-A
Loss of the CVR Recording Logic relays

1. Possible Causes

RCDR PWR/FLT CTL relay (6RK)
wiring
RCDR PWR/ENG CTL relay (8RK)
CVR PWR CUT OFF relay (10RK)

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 23-71-00-710-002	Operational Test of the CVR Recording Logic Including Time Delay Relay
ASM 237101

3. Fault Confirmation
Subtask 23-71-00-710-060-A

A. Test
(1) Do the Operational Test of the CVR Recording Logic Including Time Delay Relay AMM 23-71-00-710-002.

4. Fault Isolation
Subtask 23-71-00-810-056-A ** ON A/C NOT FOR ALL

A. If during the operational test you do not hear the conversations from the CVR microphone in the headset or cockpit loudspeakers:
(1) Do a check for continuity at the RCDR PWR/FLT CTL relay (6RK) (between pins A and 2, pins B and 4, pins C and 6, pins X and Z) ASM 237101.
(a) If there is no continuity:

replace the RCDR PWR/FLT CTL relay (6RK),
do the test(s) given in the Para. Fault Confirmation.

(b) If there is continuity:

do a check and repair the wiring from the RCDR PWR/FLT CTL relay (6RK) pin 2 to the first terminal block ASM 237101,
do the test(s) given in the Para. Fault Confirmation.

(2) If the fault continues:
(a) Do a check for continuity at the RCDR PWR/ENG CTL relay (8RK) (between pins A and 1, pins B and 3, pins C and 5, pins X and Z).
1 If there is no continuity:

replace the RCDR PWR/ENG CTL relay (8RK),
do the test(s) given in the Para. Fault Confirmation.

2 If there is continuity:

do a check and repair the wiring from the RCDR PWR/ENG CTL relay (8RK) pin 1 to the first terminal block ASM 237101,
do the test(s) given in the Para. Fault Confirmation.

(3) If the fault continues:
(a) Do a check for continuity at the CVR PWR CUT OFF relay (10RK) (between pins B1 and B2 and pins X1 and X2) ASM 237101.
1 If there is no continuity:

replace the CVR PWR CUT OFF relay (10RK),
do the test(s) given in the Para. Fault Confirmation.

2 If there is continuity:

do a check and repair the wiring from the CVR PWR CUT OFF relay (10RK) pin B2 to the RCDR PWR/ENG CTL relay (8RK) pin Z ASM 237101,
do the test(s) given in the Para. Fault Confirmation.

(4) If the fault continues:
(a) Do a check and repair if necessary the wiring ASM 237101 between:

the RCDR PWR/ENG CTL relay (8RK) pins X, Z and the CVR PWR CUT OFF relay (10RK) pins X1, B2,
the RCDR PWR/ENG CTL relay (8RK) pins A, B and the RCDR PWR/FLT CTL relay (6RK) pins A, B,
the RCDR PWR/ENG CTL relay (8RK) pins C, 1 and the RCDR PWR/FLT CTL relay (6RK) pins C, 2,
the RCDR PWR/ENG CTL relay (8RK) pins 3, 5 and the RCDR PWR/FLT CTL relay (6RK) pins 4, 6.

(b) Do the test(s) given in the Para. Fault Confirmation.
(5) If the fault continues:
(a) Do a check of the wiring for 28VDC from the C/B 4RK to the RCDR PWR/FLT CTL relay (6RK) pin X ASM 237101.
1 If there is no 28VDC:

repair the above wiring,
do the test(s) given in the Para. Fault Confirmation.

2 If there is 28VDC:

continue the troubleshooting.

(b) Do a check of the wiring for 28VDC from the C/B 4RK to the RCDR PWR/ENG CTL relay (8RK) pin X ASM 237101.
1 If there is no 28VDC:

repair the above wiring,
do the test(s) given in the Para. Fault Confirmation.

2 If there is 28VDC:

continue the troubleshooting.

(c) Do a check of the wiring for 115VAC from the C/B 2RK to the RCDR PWR/ENG CTL (8RK) pin A ASM 237101.
1 If there is no 115VAC:

repair the above wiring,
do the test(s) given in the Para. Fault Confirmation.

2 If there is 115VAC:

do the test(s) given in the Para. Fault Confirmation.

Subtask 23-71-00-810-056-B ** ON A/C NOT FOR ALL

replace the RCDR PWR/FLT CTL relay (6RK),
do the test(s) given in the Para. Fault Confirmation.

(b) If there is continuity:

continue the troubleshooting.

(2) If the fault continues:
(a) Do a check for continuity at the RCDR PWR/ENG CTL relay (8RK) (between pins A and 1, pins B and 3, pins C and 5, pins X and Z).
1 If there is no continuity:

replace the RCDR PWR/ENG CTL relay (8RK),
do the test(s) given in the Para. Fault Confirmation.

2 If there is continuity:

continue the troubleshooting.

(3) If the fault continues:
(a) Do a check for continuity at the CVR PWR CUT OFF relay (10RK) (between pins A3 and A2, pins B1 and B2 and pins X1 and X2) ASM 237101.
1 If there is no continuity:

replace the CVR PWR CUT OFF relay (10RK),
do the test(s) given in the Para. Fault Confirmation.

2 If there is continuity:

continue the troubleshooting.

(4) If the fault continues:
(a) Do a check and repair if necessary the wiring ASM 237101 between:

the RCDR PWR/FLT CTL relay (6RK) pins A, 2 and the CVR PWR CUT OFF relay (10RK) pins A2, A3,
the RCDR PWR/ENG CTL relay (8RK) pins X, 1, Z and the CVR PWR CUT OFF relay (10RK) pins X1, A3, B2,
the RCDR PWR/ENG CTL relay (8RK) pins A, B and the RCDR PWR/FLT CTL relay (6RK) pins A, B,
the RCDR PWR/ENG CTL relay (8RK) pins C, 1 and the RCDR PWR/FLT CTL relay (6RK) pins C, 2,
the RCDR PWR/ENG CTL relay (8RK) pins 3, 5 and the RCDR PWR/FLT CTL relay (6RK) pins 4, 6.

(b) Do the test(s) given in the Para. Fault Confirmation.
(5) If the fault continues:
(a) Do a check of the wiring for 28VDC from the C/B 26RK to the RCDR PWR/FLT CTL (6RK) pin X ASM 237101.
1 If there is no 28VDC:

repair the above wiring,
do the test(s) given in the Para. Fault Confirmation.

2 If there is 28VDC:

continue the troubleshooting.

(b) Do a check of the wiring for 28VDC from the C/B 26RK to the RCDR PWR/ENG CTL relay (8RK) pin X ASM 237101.
1 If there is no 28VDC:

repair the above wiring,
do the test(s) given in the Para. Fault Confirmation.

2 If there is 28VDC:

continue the troubleshooting.

repair the above wiring,
do the test(s) given in the Para. Fault Confirmation.

2 If there is 28VDC:

do the test(s) given in the Para. Fault Confirmation.

[Rev.8 from Aug 2018] 2026.04.04 04:25:47 UTC