−
55
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FILE NO. SVM-04007
9-6. Troubleshooting for Indoor unit
9-6-1. Power can not be turned on. (The unit does not operate at all.)
<Primary check>
(1)
Is the supply voltage normal?
(2)
Is the connection to the AC output OK?
(3)
Are the connection of the primary side and the secondary side
of the power transformer inserted into the P.C. board?
(4)
Is the fuse (F01) blown?
NO
NO NO
NO
NO
NO
NO
NO
NO
YES
YES
YES
YES
YES
YES
YES
YES
YES
Is DC
310
−
340V
supplied to
primary side
of transfer
switch?
Are DC 15V,
DC 12V and
DC 7V
supplied to
secondary
side of
transfer
switch?
Refer to
<Primary check>
or this problem
is one step short
of power P.C.
board block.
Turn off breaker
once and turn it
on again after
removing motor.
Is voltage
(DC 12V or 5V)
indicated on rear
of indoor control
board normal?
Is fuse (F01)
of indoor
control board
blown?
Parts (R21,
R22, SG01,
C15, C01, DB01,
C02, IC01
and T01)
are defective.
Are DC 15V,
DC 12V or
DC 7V
supplied to
secondary
side of
transfer
switch?
Transfer switch,
IC (IC01) for
power supply
or fan motor
is defective.
Replace motor.
Does the
fan motor
connector
between
1
and
2
short-circuit?
Microcomputer
is defective.
Unit operates
normally.
Replace main
P.C. board.
Remote control
is defective.
Refer to 9-9
Troubleshooting for
Remote Control.
Does
transmission
mark on
remote control
flash normally,
and is its
signal
transmitted
properly?
Turn off power supply
once, and 5 second
later, turn it on again.
Is OPERATION
lamp blinking?
Is it possible to
turn on power
supply by pressing
[START/STOP]
button on
remote control?
Operation
Check item
Conceivable principle cause
Measure
Item by symptoms
