30
Check of indoor electronic control P.C. board and indoor fan motor
C
1. Please replace the fuse after removing
the indoor terminal P.C. board from
the electrical box.
Yes
No
Does the unit operate with the remote controller?
Does OPERATION INDICATOR lamp light up by
pressing EMERGENCY OPERATION switch?
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.
Measure the resistance of the vane motor coil.
Refer to 10-5.
Measure the resistance of indoor fan motor.
Refer to 10-5.
Short circuit
Replace the indoor fan motor.
Short circuit
Replace the vane motor and the indoor
electronic control P.C. board.
Turn OFF the power supply.
Check both “parts side” and “pattern
side” of the indoor terminal P.C.
board visually.
Replace the varistor (NR11) and fuse (F11). 1
Are the varistor (NR11) burnt
and the fuse (F11) blown?
Be sure to check both the fuse
and the varistor in any case.
No
Yes
No
Is the fuse (F11) blown only?
Yes
No
Is there approximately 5 VDC between
5 VDC (+) and JPG (GND) (-) of the indoor
electronic control P.C.board?
Is there approximately 9 VDC to 13 VDC between
12 VDC (+) and JPG (GND) (-) of the indoor
electronic control P.C. board?
Replace the fuse (F11). 1
Replace the fuse (F11) and
indoor fan motor. 1
Is the resistance of resistor
Measure the resistance of the reisistor
(R111) on the indoor power
P.C. board.
Yes
Connect the connector or repair
disconnection.
Yes
No
Are connector CN10A on
the indoor electronic control
P.C. board or lead wires
disconnected?
No
Replace the indoor power/terminal P.C. board.
Replace the indoor power/terminal P.C. board
and the indoor fan motor.
Yes
Measure the resistance of indoor
fan motor.
Refer to 10-5.
Is the resistance normal?
No
Yes
Replace the fan motor.
JPG (GND)
12 VDC
5 VDC
CN10A
Indoor power P.C.board
Indoor electronic
control P.C.board
Fuse (F11)
Indoor terminal
P.C.board
Varistor
(NR11)
R111
CN211
(R111) approximately 4
Ω
?
MS-GF20/25/35VA
OBH621A