Mitsubishi Electric MSZ-EF VE Series Service Manual page 104

The cooling operation or the heating operation does not operate.
Check of R.V. coil
MXZ-2D33VA/2D40VA/2D42VA/2D53VA/2D53VAH
• The heating operation does not operate.
1. Disconnect the lead wire leading to the compressor.
2. 3 minutes after turning ON the breaker, start EMERGENCY
OPERATION in HEAT mode.
Is there voltage of 230 VAC between pin 1 and
pin 2 at connector CN721?
Yes
Turn OFF the breaker. Disconnect the connector CN721.
Is there normal resistance
to R.V. coil?
(Refer to 11-5.)
Yes
Replace the 4-way valve.
• The cooling operation does not operate.
1. Disconnect the lead wire leading to the compressor.
2. 3 minutes after turning ON the breaker, start EMERGENCY
OPERATION in COOL mode.
Is there voltage of 230 VAC between pin 1 and
pin 2 at connector CN721?
No
Replace the 4-way valve.
OBH626E
No
No
Replace the R.V. coil.
Yes
Replace the inverter P.C. board.
Replace the inverter P.C. board.
104
MXZ-2D
CN721 Inverter P.C. board