R **ON A/C 002-049, 053-099, 101-149, 151-199, 201-299, 301-399, 401-499,
B. If the test gives the maintenance message AMU(1RN):
- do a check of the circuit breakers (8RN and 9RN) status.
(1) If the two circuit breakers (8RN and 9RN) are closed:
- do a check for 28VDC at pins AC/9, 10 of the AMU (1RN) (Ref. ASM 23-51/06).
(a) If there is 28VDC at the two pins:
- do a check at the 28VDC POWER SUPPLY signal of each card of the AMU (1RN): . For the AMU Card 1, 28VDC at pin AC/1 of the AMU (1RN) (Ref. ASM 23-51/02) . For the AMU Card 2, 28VDC at pin AC/4 of the AMU (1RN) (Ref. ASM 23-51/03) . For the AMU Card 3, 28VDC at pin AC/5 of the AMU (1RN) (Ref. ASM 23-51/04).
1 If there is 28VDC at each pin:
_
- replace the AMU (1RN) (Ref. AMM TASK 23-51-34-000-001) and (Ref. AMM TASK 23-51-34-400-001).
2 If there is no 28VDC at each pin:
_
- do a check of the ground and repair the wiring between AMU (1RN) pins AC/7, 8 and the ground terminal (Ref. ASM 23-51/03) and (Ref. ASM 23-51/04).
3 If there is no 28VDC at one of the pins:
_
- replace the AMU (1RN) (Ref. AMM TASK 23-51-34-000-001) and (Ref. AMM TASK 23-51-34-400-001).
a If the fault continues:
_
- repair the wiring between that faulty pin and the first terminal block.
(b) If there is no 28VDC at the two pins:
- do a check of the ground and repair the wiring between AMU (1RN) pins AC/7, 8 and the ground terminal (Ref. ASM 23-51/03) and (Ref. ASM 23-51/04).
(c) If there is no 28VDC at pin AC/9 of the AMU (1RN):
- replace the AMU (1RN) (Ref. AMM TASK 23-51-34-000-001) and (Ref. AMM TASK 23-51-34-400-001).
1 If the fault continues:
_
- do a check of the wiring between AMU (1RN) pin AC/9 and the circuit breaker (9RN) (Ref. ASM 23-51/06).
a If there is no continuity:
_ - repair the above wiring.
「一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一1R EFF : 002-049, 053-099, 101-149, 151-199, ∞∞23-51-00∞∞∞∞∞∞∞∞∞∞Page 213
201-299, 301-399, 401-499, Aug 01/05 CES b If there is continuity:
_ - replace the C/B - COM/AUDIO/FLT/INTPH (9RN).
(d) If there is no 28VDC at pin AC/10 of the AMU (1RN):
- replace the AMU (1RN) (Ref. AMM TASK 23-51-34-000-001) and (Ref. AMM TASK 23-51-34-400-001).
1 If the fault continues:
_
- do a check of the wiring between AMU (1RN) pin AC/10 and the circuit breaker (8RN) (Ref. ASM 23-51/06).
a If there is no continuity:
_
- repair the above wiring. b If there is continuity:
_
- replace the C/B - COM NAV/SELCAL (8RN).
(2) If the circuit breaker (9RN) is open:
- close it.
(a) If it opens again:
- replace the AMU (1RN) (Ref. AMM TASK 23-51-34-000-001) and (Ref. AMM TASK 23-51-34-400-001).
1 If the fault continues:
_
- do a check for a short to ground at the wiring between AMU (1RN) pin AC/9 and the circuit breaker (9RN) (Ref. ASM 23-51/06).
a If there is a short to ground:
_
- repair the related wiring. b If there is no short to ground:
_ - replace the C/B - COM/AUDIO/FLT/INTPH (9RN).
(3) If the circuit breaker (8RN) is open:
- close it.
(a) If it opens again:
- replace the AMU (1RN) (Ref. AMM TASK 23-51-34-000-001) and (Ref. AMM TASK 23-51-34-400-001).
1 If the fault continues:
_
- do a check for a short to ground at the wiring between AMU (1RN) pin AC/10 and the circuit breaker (8RN) (Ref. ASM 23-51/06).
a If there is a short to ground:
_
- repair the related wiring. b If there is no short to ground:
_
- replace the C/B - COM NAV/SELCAL (8RN).
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本文链接地址：A320 Trouble Shooting Manual 排故手册 COMMUNICATIONS 通讯2(7)
