3-3 Fault Diagnosis by Symptom
3-3-1 No Power (completely dead)-Initial diagnosis
1)Checklist :
(1)Is input voltage normal?
(2)Is AC power linked correctly?
(3)Is output voltage of DC regulator IC KA7805 (IC02) normal?
2)Troubleshooting procedure
Remove power cord and plug in
again in approx. 5 seconds
YES
Replace
PCB display
Is operation lamp blinking?
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| YES | |||
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Is DC voltage of PCB | Does operation start when | |||||||||||
run/stop button on the remote | ||||||||||||
display normal? | ||||||||||||
controller unit pushed? | ||||||||||||
| NO |
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| NO | ||||
Is rating voltage ±10% | Is transmission display of the | |||||||||||
range applied to the | remote controller unit blinking? | |||||||||||
primary side (~,~) |
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| YES | ||||
of the “BD71” |
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Is "beep"sound heard from the | ||||||||||||
| NO | |||||||||||
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| main unit? | |||||
| NO |
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•Check linkage between |
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| YES | ||||
power cord and | Is DC voltage of the PCB module | |||||||||||
terminal tap |
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•Check fuse |
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| YES | |||
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| 5VDC Is voltage of #60 (indoor fan) | ||||||||||
Is 14~18VAC | appear in | of the micom normal? | ||||||||||
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the secondary side (+, |
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of “BD71” | DC5V |
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NO | YES |
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| 10ms | |||||
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| NO |
YES | Normal |
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NO | Refer to remote control |
| unit fault diagnosis |
NO | Replace PCB module. |
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YES | DC12V |
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| Is voltage at SS71(indoor fan) | |
| YES | NO |
Check connections
compressor
Replace RY71,
Replace
valve, outdoor fan and
RY73, RY72 and
SMPS PARTS
indoor fan.
SS71
NO
Replace resonator (X301)
Is operation normal?
Is output voltage of ICO2 normal?
Is voltage at #52 terminal of the |
| YES | NO | |
micom normal? |
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| Check PCB pattern. | Replace ICO2 | ||
10ms | Replace main PCB. | |||
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YES | NO |
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Is voltage output | terminal of | |||
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Are voltage at #48 and #49 of the | TLP180(PC02) normal? | |||
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micom normal? |
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| YES | NO | |
250ns | OK | Replace TLP180(pc02) | ||
YES | ||||
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YES
OK
NO
Replace micom
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