W DOC AIRBUS | TSM A320F

Loss of the Lower ECAM DU

TASK 31-63-82-810-808-A
Loss of the Lower ECAM DU

1. Possible Causes
  • DU-ECAM, LOWER [4WT2]
  • wiring
  • C/B-EIS/ECAM DU/LOWER/SPLY [13WT2]
  • CTL PNL-ECAM [6WT]
  • C/B-EIS/ECAM DU/LOWER/SWTG [24WT2]
  • DMC-3 [1WT3]
  • RELAY-BUS1 TO ESS BUS SWTG, DMC3 [26WT]
  • C/B-EIS/DMC3/SPLY [10WT3]
  • C/B-EIS/DMC3/SWTG [21WT3]
  • SEL SW-EIS DMC [18WT]
  • DMC-2 [1WT2]
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 31-61-12-000-001
Removal of the ECAM Control Panel
AMM 31-61-12-400-001
Installation of the ECAM Control Panel
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
3. Fault Confirmation
Subtask 31-63-82-860-064-A ** ON A/C NOT FOR ALL
A. Job Set-up
Do the EIS start procedure (lower ECAM DU only) AMM 31-60-00-860-001.
Subtask 31-63-82-700-064-A ** ON A/C NOT FOR ALL
B. Test
Make sure that the lower ECAM DU stays off.
4. Fault Isolation
Subtask 31-63-82-810-064-A ** ON A/C NOT FOR ALL
A. If the lower ECAM DU 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 lower ECAM DU (4WT2) 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 lower ECAM DU (4WT2).
       1 If there is no ground signal:
  • repair the wiring from lower ECAM DU (4WT2) pin AA/102 to the ground terminal.
       2 If there is a ground signal:
  • do a check of the wiring from lower ECAM DU (4WT2) pin AA/104 to the circuit breaker (13WT2).
         a If there is no continuity:
  • repair the wiring.
         b If there is continuity:
  • replace the C/B-EIS/ECAM DU/LOWER/SPLY [13WT2] .
   (2) If the fault continues:
  • do a check of the wiring from lower ECAM DU (4WT2) pins AA/49, 50, 51 to ECAM control panel (6WT) pins B/B, C, U ASM 316801.
     (a) If there is continuity:
       1 If the fault continues:
     (b) If there is no continuity:
  • repair the wiring from lower ECAM DU (4WT2) pins AA/49, 50, 51 to ECAM control panel (6WT) pins B/B, C, U.
Subtask 31-63-82-810-065-A ** ON A/C NOT FOR ALL
B. If the lower ECAM DU stays off and if the EIS DMC selector switch (18WT) on the SWITCHING panel 8VU is at F/O/3:
   (1) Do a check for 28VDC at pin AA/93 on the lower ECAM DU (4WT2) 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 lower ECAM DU (4WT2).
       1 If there is no ground signal:
  • repair the wiring from lower ECAM DU (4WT2) pin AA/106 to the ground terminal.
       2 If there is a ground signal:
  • do a check of the wiring from lower ECAM DU (4WT2) pin AA/93 to the circuit breaker (24WT2).
         a If there is no continuity:
  • repair the wiring.
         b If there is continuity:
  • replace the C/B-EIS/ECAM DU/LOWER/SWTG [24WT2] .
   (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/SPLY [10WT3] .
    . 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 A3 to the EIS/DMC3/SPLY circuit breaker (10WT3), 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 DMC2 (1WT2).
     (a) If there is no ground signal:
  • do a check for a ground signal at pin AA/4 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 4 to DMC2 (1WT2) pins 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/4H of the DMC3 (1WT3) ASM 316802.
       1 If there is no ground signal:
  • do a check of the wiring from DMC3 (1WT3) pin AB/4H to the first terminal block ASM 316802.
         a If there is no continuity:
  • repair the wiring.
         b If there is continuity:
Subtask 31-63-82-700-065-A ** ON A/C NOT FOR ALL
C. Do the EIS start procedure (lower ECAM DU only) AMM 31-60-00-860-001 and make sure that the lower ECAM DU comes on.
5. Close-up
Subtask 31-63-82-860-065-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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