Mitsubishi Electric MXZ-2C30VA Service Manual page 103

MXZ-6C120/6C122VA
• When heating operation does not work.
1. Disconnect the lead wire leading to the compressor.
2. 3 minutes after turning ON the power supply, start EMERGENCY
OPERATION in HEAT mode.
Is there voltage of 230 VAC between pin 1 and
pin 2 at connector CN712?
Yes
Turn OFF the power supply.
Disconnect the connector CN912.
Is there normal resistance
to R.V. coil? (Refer to 11-5.)
Yes
Replace the 4-way valve.
• When cooling operation does not work.
1. Disconnect the lead wire leading to the compressor.
2. 3 minutes after turning ON the power supply, start EMERGENCY
OPERATION in COOL mode.
Is there voltage of 230 VAC between pin1 and
pin 2 at connector CN712 ?
Yes
Replace the control P.C. board/outdoor
control P.C. board.
• When cooling, heat exchanger of non-operating indoor unit frosts.
• When heating, non-operating indoor unit gets warm.
Check of LEV
Turn ON the power supply to the outdoor unit after checking
LEV coil is mounted to the LEV body securely.
Is "click - click" sound heard?
Or, do you feel vibration of LEV coil with your hand?
No
Disconnect the connectors.
CN791: LEV A, CN792: LEV B, CN793: LEV C,
CN794: LEV D, CN795: LEV E, CN796: LEV F,
CN797: LEV M.
Is there normal resistance to LEV coil?
(Refer to 11-5.)
No
Replace LEV coil.
OBH584G
No
No
Replace the R.V. coil.
No
Yes
CN711
CN712
Is there voltage 230 VAC
between the pin 1 and pin 3 at
connector CN711?
Yes
Replace the control P.C. board/outdoor
control P.C. board.
Replace the 4-way valve.
MXZ-2C
CN791
Inverter
CN792
P.C. board
CN793
CN794
CN795
CN796
CN797
Yes
Normal
Replace the inverter P.C. board, the
electronic control P.C. board, the control P.C.
board, or the outdoor control P.C. board.
103
MXZ-6C120VA MXZ-6C122VA
Control P.C. Outdoor control
board P.C. board
Replace the power
No
board /outdoor power
P.C. board.
MXZ-3C/
MXZ-6C120 MXZ-6C122
4C/5C
Outdoor
Electronic Control
control P.C. board control
P.C. board P.C. board