Mitsubishi Electric MSZ-A09RV-E1 Service Manual page 50

H
Check of indoor electronic P.C. board
The unit does not operate with the remote controller. The operation indicator lamp does not light up either, with the
Emergency operation switch ON.
Check both "parts side"
Turn OFF the power supply.
and "pattern side" of indoor
Remove indoor fan motor connector CN211 and vane motor connector CN151
electronic control P.C.
from the ELECTRONIC CONTROL P.C. board and turn on the power supply.
board visually.
The unit doesn't operate with the remote controller.
Also, the Power monitor lamp doesn't light up
by pressing the EMERGENCY OPERATION switch.
varistor (NR11)
fuse (F11)
Indoor electronic
control P.C. board
I
Check of outdoor thermistors
The thermistors in the outdoor unit are abnormal.
Disconnect the connectors CN 641 and CN 642 from the outdoor electronic control P.C. board.
(Check the characteristics of each thermistor.)
(Defrost thermistor)
Measure
resistance
between. CN
6411 and 2
( )
Discharge
temperature
thermistor
Measure
resistance
between. CN
6413 and 4
( )
Fin
temperature
thermistor
Measure
resistance
between. CN
6421 and 2
No
Replace the vane motor. .
Yes
Is winding resistance
of vane motor 0 "?
Be sure to check both resistance.
Is winding resistance
of fan motor 0 "?
Yes
Replace the fan motor .
1 Connect CN 641 and
CN 642.
2 Disconnect the
connector between
compressor and IPM.
As per the
Yes
characteristics
on page 55?
No
Turn on power to
indoor unit and
Thermistor is
press Emergency
defective.
operation switch
No
As per the
characteristics
on page 55? Yes
Yes
Replace the fuse.
No
Is fuse(F11) blown?
Be sure to check both fuse
and varistor in any case.
Is varistor(NR11) burnt?
No
Replace the varistor.
Inferior electronic control
P.C. board
Does the unit operate
10 minutes or more?
Is LED in the electronic
control P.C. board
flashing 5 minutes?
Disconnecting connector
or inferior connecting
50
indoor electronic
thermal fuse connector
control P.C. board
1
3
Yes
No
Trouble of the
indoor electronic
control P.C. board.
No
Yes
No
Yes
Yes
No
N
2
3
Thermal
block