Service manual

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11-4. Judgment of Trouble by Every Symptom
11-4-1. Indoor Unit (Including Remote Controller)
(1) Power is not turned on (Does not operate entirely)
<Primary check>
1. Is the supply voltage normal?
2. Is the normal voltage provided to the outdoor unit?
3. Is the crossover cable connected properly?
4. Is the fuse (F01) blown?
• Be sure to disconnect the motor connector CN10 after shut off the power supply, or it will be a cause of
damage of the motor.
(2) Power is not turned on though Indoor P.C. board is replaced
<Confirmation procedure>
NO
Turn off power supply once, and
5 second later, turn it on again.
Is OPERATION indicator flashing?
Is it possible to turn on
power supply by pushing
[START/STOP] button
on remote controller?
Is voltage
(DC12V or 5V)
indicated on rear of
indoor control
board normal?
Does transmission mark
on remote controller flash
normally,and is its signal
transmitted properly?
Is DC310–340V
supplied between
CN10 1 – 3 ?
Does fan
motor connector
between CN10 1 –
3 short-circuit?
Item by symptoms
Operation
Check Item
Considerable principle cause
Measures
Parts (R04, R05, DB01, C01,
C03, IC01 and T01) are defective.
Remote controller is defective.
Refer to (5) “Troubleshooting
for remote controller”.
Parts of a power supply circuit
defective.
Unit operates normally.
Replace main
P.C. board
Replace fan
motor.
Is fuse (F01)
of indoor control
board blown?
Microcomputer
is defective.
NO
NO
NO
NO NO
NO
YES
YES
YES
YES YES
YES YES
YES YES
NO
NO
To item of
“Power supply is not turned on”.
Turn on power supply.
Does OPERATION indicator flash?
Is wired correctly to white and
black lead wires of terminal block?
Correct wiring.