23
C Check of indoor P.C. board and indoor fan motor
Turn OFF the power supply.
Remove indoor fan motor connector CN211
from indoor power P.C. board and vane
motor connector CN151 from the indoor
electronic control P.C. board and turn ON
the power supply.
Does the unit operate with the remote
controller?
Does OPERATION INDICATOR lamp light
up by pressing the emergency operation
switch?
Yes
No
Measure the resistance of indoor fan
motor.
Refer to 10-5.
Short circuit:
Replace the indoor fan motor.
Turn OFF the power supply.
Check both “parts side” and “pattern
side” of the indoor power P.C. board
visually.
Replace the varistor (NR11)
and fuse (F11).
*
3
Are the varistor (NR11)
burnt and the fuse (F11)
blown?
No
No
Yes
Yes
Be sure to check both the fuse
and the varistor in any case.
Is the fuse (F11) blown
only?
Measure the resistance between
CN211 (+) and (-) of indoor fan
motor connector.
*
1,
*
2
Yes
Is the resistance 1MΩ or more?
Replace the fuse (F11) and the
indoor fan motor.
*
3
No
Replace the fuse (F11).
*
3
Measure the resistance of resistor (R111)
on the indoor power P.C. board.
No
No
Replace the indoor
power P.C. board,
indoor fan motor.
Replace the indoor power P.C. board.
Measure the resistance of the vane
motor coil.
Refer to 10-5.
Short circuit:
Replace the vane motor and the indoor
electronic control P.C. board.
*
1. The fan motor connector's lead wire is red,
whereas is black.
*
2. Connect "+" of the multimeter to fan motor
connector's lead wire, and “-” to lead wire,
otherwise the resistance cannot be measured
properly.
*
3. Please replace the fuse after removing the
indoor power P.C. board from the electrical
box.
Is there approximately 5 V DC between
5 V (+) and GND (-) of the indoor
electronic control P.C. board? Is there
approximately 9 V to 13 V DC between
12 V (+) and GND (-) of the indoor
electronic control P.C. board?
Is the connector CN10A on
the indoor electronic control
P.C. board or lead wires
disconnected?
Yes
Replace the indoor
fan motor.
Yes
Connect the connec-
tor CN10A or repair
disconnection.
No
Is the resistance of resistor (R111)
approximately 4 Ω ?
Yes
With a multimeter, check
the continuity between the
connector CN201 on the
indoor control P.C. board and
S2 on the terminal block.
Is electricity
conducted? (The
resistance is 0 Ω.)
Yes
No
The thermal fuse connected
to the terminal block has
failed.
Replace the terminal block
assembly.
Indoor electronic control P.C. board
CN10A
12 V DC
5 V DC
Indoor power P.C. board
CN211
Fuse
(F11)
Varistor
(NR11)
Is there approximately 5 V DC between
5 V (+) and GND (-) of the indoor
power P.C. board? Is there approxi-
mately 9 V to 13 V DC between 12 V (+)
and GND (-) of the indoor power P.C.
board?
No
Yes
Replace the indoor
electronic control.
GND
R111
OBH905
