11-5. Judgment of Trouble by Every Symptom 
11-5-1. 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?
•
B
e s
ure to disconnect the motor connector CN10 after shut off the power supply, or it will be a cause of
damage of the motor
.
Operation
Measure
Item by symptoms
Check item
Conceivable principle 
cause
Parts
(DB01,C08,T01
and IC01)
are defective.
"Troubleshooting for
DC 310V~340V?
3
Turn off power
supply once, and 5
second later, turn it
on again.
Is OPERATION
lamp blinking?
NO
YES
NO
NO
YES
YES
Is it possible to
turn on power
supply by pressing
 [    ]
button
on remote
control?
Does
transmission
mark on
remote control
flash normally,
and is its signal
transmitted
properly?
Remote control is
defective.
Refer to (4)
Remote Control.
"
Is fuse (F01)
of indoor control
board blown?
Is voltage
(DC 12V or 5V)
indicated on
rear of indoor
control board
normal?
Microcomputer
is defective.
Replace main
P.C. board.
Refer to
<Primary check>
or this problem
is one step short
of power P.C.
Is the
voltage
across C08
mesured 
YES
YES
NO
NO
NO
NO
YES
Does
fan motor
connector
between 1
and
short-circuit?
Unit operates
normally.
board block.
Are DC 5V,
DC 12V 
supplied 
to main
P.C. board?
Turn off breaker
once and turn it
on again after
removing motor.
Regulator IC
(IC02) or T01
are defective
Replace motor
.
NO 
NO
YES
YES YES
Are DC 5V,
or DC 12V
supplied
to main 
P.C. board?
3. Is the crossover cable connected properly?
4. Is the fus
e (F01) blown?
(For 
B05, 
07, 
10, 
13, 
16K)