W DOC AIRBUS | TSM A320F

Loss of the CAPT ND

TASK 31-63-82-810-804-A
Loss of the CAPT ND

1. Possible Causes
  • ND-CAPT [3WT1]
  • wiring
  • C/B-EIS/ND CAPT/SPLY [12WT1]
  • POT-ND, CAPT [8WT1]
  • C/B-EIS/ND CAPT/SWTG [23WT1]
  • DMC-3 [1WT3]
  • RELAY-BUS1 TO ESS BUS SWTG, DMC3 [26WT]
  • C/B-EIS/DMC3/STBY/SPLY [14WT1]
  • C/B-EIS/DMC3/SWTG [21WT3]
  • SEL SW-EIS DMC [18WT]
  • DMC-1 [1WT1]
2. Job Set-up Information
 A. Referenced Information
REFERENCE
DESIGNATION
AMM 31-60-00-860-001
EIS Start Procedure
AMM 31-60-00-860-002
EIS Stop Procedure
ASM 316102
AMM 31-63-22-000-001
Removal of the Display Unit
AMM 31-63-22-400-001
Installation of the Display Unit
AMM 31-63-34-000-001
Removal of the DMC
AMM 31-63-34-400-001
Installation of the DMC
ASM 316801
ASM 316802
AIPC 316808
3. Fault Confirmation
Subtask 31-63-82-860-056-A ** ON A/C NOT FOR ALL
A. Job Set-up
Do the EIS start procedure (CAPT ND only) AMM 31-60-00-860-001.
Subtask 31-63-82-700-056-A ** ON A/C NOT FOR ALL
B. Test
Make sure that the CAPT ND stays off.
4. Fault Isolation
Subtask 31-63-82-810-056-A ** ON A/C NOT FOR ALL
A. If the CAPT ND stays off and if the EIS DMC selector switch (18WT) on the SWITCHING panel 8VU is at NORM:
   (1) Do a check for 115VAC at pin AA/104 of the CAPT ND (3WT1) ASM 316102.
     (a) If there is 115VAC:
     (b) If there is no 115VAC:
  • do a check for a ground signal at pin AA/102 of the CAPT ND (3WT1).
       1 If there is no ground signal:
  • repair the wiring from CAPT ND (3WT1) pin AA/102 to the ground terminal.
       2 If there is a ground signal:
  • do a check of the wiring from CAPT ND (3WT1) pin AA/104 to the circuit breaker (12WT1).
         a If there is no continuity:
  • repair the wiring.
         b If there is continuity:
  • replace the C/B-EIS/ND CAPT/SPLY [12WT1] .
   (2) If the fault continues:
  • do a check of the wiring from CAPT ND (3WT1) pins AA/49, 50, 51, 52 to CAPT ND potentiometer (8WT1) pins A/2, 4, 5, 6 ASM 316801.
     (a) If there is continuity:
       1 If the fault continues:
     (b) If there is no continuity:
  • repair the wiring from CAPT ND (3WT1) pins AA/49, 50, 51, 52 to CAPT ND potentiometer (8WT1) pins A/2, 4, 5, 6.
Subtask 31-63-82-810-057-A ** ON A/C NOT FOR ALL
B. If the CAPT ND stays off and if the EIS DMC selector switch (18WT) on the SWITCHING panel 8VU is at CAPT/3:
   (1) Do a check for 28VDC at pin AA/93 on the CAPT ND (3WT1) ASM 316102.
     (a) If there is 28VDC:
     (b) If there is no 28VDC:
  • do a check for a ground signal at pin AA/106 of the CAPT ND (3WT1).
       1 If there is no ground signal:
  • repair the wiring from CAPT ND (3WT1) pin AA/106 to the ground terminal.
       2 If there is a ground signal:
  • do a check of the wiring from CAPT ND (3WT1) pin AA/93 to the circuit breaker (23WT1).
         a If there is no continuity:
  • repair the wiring.
         b If there is continuity:
  • replace the C/B-EIS/ND CAPT/SWTG [23WT1]
   (2) If the fault continues:
  • do a check for 115VAC at pin AC/2 of the DMC3 (1WT3) ASM 316102.
     (a) If there is 115VAC:
     (b) If there is no 115VAC:
  • do a check for a ground signal at pin AC/7 of the DMC3 (1WT3).
       1 If there is no ground signal:
  • repair the wiring from DMC3 (1WT3) pin AC/7 to the ground terminal.
       2 If there is a ground signal:
  • replace the RELAY-BUS1 TO ESS BUS SWTG, DMC3 [26WT] .
         a If the fault continues:
  • replace the C/B-EIS/DMC3/STBY/SPLY [14WT1]
    . If the fault continues:
    * do a check of the wiring from the DMC3 BUS1 TO ESS BUS SWTG relay (26WT):
    . pin A2 to DMC3 (1WT3) pin AC/2
    . pin A1 t the EIS/DMC3/STBY/SPLY circuit breaker (14WT1)
    . pin X2 to the BUS 1XP CTL relay (20XN1)
    * repair the wiring which has no continuity.
   (3) If the fault continues:
  • do a check for 28VDC at pin AC/3 of the DMC3 (1WT3) ASM 316102.
     (a) If there is 28VDC:
     (b) If there is no 28VDC:
  • do a check for a ground signal at pin AC/11 of the DMC3 (1WT3) ASM 316102.
       1 If there is no ground signal:
  • repair the wiring from DMC3 (1WT3) pin AC/11 to the ground terminal.
       2 If there is a ground signal:
  • do a check of the wiring from DMC3 (1WT3) pin AC/3 to the circuit breaker (21WT3) ASM 316102.
         a If there is no continuity:
  • repair the wiring.
         b If there is continuity:
  • replace the C/B-EIS/DMC3/SWTG [21WT3] .
   (4) If the fault continues:
  • do a check for a ground signal at pin AB/8H, 4C of the DMC1 (1WT1).
     (a) If there is no ground signal:
  • do a check for a ground signal at pin AA/2 of the EIS DMC selector switch (18WT) ASM 316802.
       1 If there is no ground signal:
  • replace the SEL SW-EIS DMC [18WT] .
       2 If there is a ground signal:
  • do a check of the wiring from EIS DMC selector switch (18WT) pin 2 to DMC1 (1WT1) pin AB/8H, 4C.
         a If there is no continuity:
  • repair the wiring.
         b If there is continuity:
     (b) If there is a ground signal:
  • do a check for a ground signal at pin AB/4C of the DMC3 (1WT3) ASM 316802.
       1 If there is no ground signal:
  • do a check of the wiring from DMC3 (1WT3) pin AB/4C to the first terminal block ASM 316802.
         a If there is no continuity:
  • repair the wiring.
         b If there is continuity:
Subtask 31-63-82-700-057-A ** ON A/C NOT FOR ALL
C. Do the EIS start procedure (CAPT ND only) AMM 31-60-00-860-001 and make sure that the CAPT ND comes on.
5. Close-up
Subtask 31-63-82-860-057-A ** ON A/C NOT FOR ALL
A. Do the EIS stop procedure AMM 31-60-00-860-002.
[Rev.8 from Aug 2018] 2026.04.04 04:31:14 UTC
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