Toshiba MXZ-2DM40VA Service Manual page 38

• The thermistor is abnormal.
Check of outdoor thermistors
Disconnect the connector in the following table.
Is the resistance of the thermistor normal? (Refer to 11-5.)
Yes
Reconnect the connector and disconnect the lead wire
leading to the compressor.
3 minutes after turning ON the breaker, start
EMERGENCY OPERATION.
Does the unit operate 10 minutes or more without
showing thermistor abnormality?
Yes
Normal
MXZ-2DM40VA
Thermistor
Defrost
Discharge temperature
Fin temperature
Ambient temperature
Outdoor heat exchanger temperature
MXZ-3DM50VA
Thermistor
Defrost
Discharge temperature
Fin temperature
Ambient temperature
Outdoor heat exchanger temperature
OBH739A
No
Replace the inverter P.C. board, outdoor
No
control P.C. board or the outdoor power
P.C. board.
Symbol Connector, Pin No.
RT61 CN641 pin1 and pin2
CN641 pin3 and pin4
RT62
RT64 CN642 pin1 and pin2
CN643 pin1 and pin2
RT65
RT68 CN644 pin1 and pin3
Symbol Connector, Pin No.
RT61 CN661 pin1 and pin2
RT62 CN661 pin3 and pin4
CN9 pin1 and pin2
RT64
RT65 CN665 pin1 and pin2
CN661 pin7 and pin8
RT68
38
Replace the thermistor except RT64.
In case that RT64 is abnormal,
replace the inverter P.C. board or the
outdoor power P.C. board since RT64
is combined with this board.
Board
Inverter P.C. board
Board
Outdoor control P.C. board
Outdoor power P.C. board
Outdoor control P.C. board