Mitsubishi Electric MSZ-LN-VG Series Service Manual page 109

12-6. TROUBLESHOOTING FLOW
Outdoor unit does not operate.
Check of power supply
MXZ-2F33VF/2F42VF/2F53VF/2F53VFH
MXZ-2F33VF2/2F42VF2/2F53VF2/2F53VFH2
MXZ-2F33VF3/2F42VF3/2F53VF3/2F53VFH3
Check the main power supply circuit for proper connections.
Turn ON the power supply.
Is there voltage of 220 - 230 - 240 V AC
in the power supply terminal block?
Yes
Is there voltage of 220 - 230 - 240 V AC
between LD66B and X64
the inverter P.C. board?
Yes
Is there voltage of 220 - 230 - 240 V AC
between LD66A and LD70 on the
inverter P.C. board?
Yes
Is there voltage of 311 - 339 V DC
between DB61 + and DB61
inverter P.C. board?
Yes
Is there voltage of 5 V DC between
CN936 and CN936
outdoor display P.C. board?
Yes
Replace the outdoor display P.C. board.
MXZ-3F54VF/3F68VF/4F72VF
MXZ-3F54VF2/3F68VF2/4F72VF2/4F80VF2
MXZ-3F54VF3/3F68VF3/4F72VF3/4F80VF3
Check the main power supply circuit for proper connections.
Turn ON the power supply.
Is there voltage of 220 - 230 - 240 V AC
in the power supply terminal block?
Yes
Is the output voltage from the outdoor
power P.C. board 311 - 339 V DC?
No
Turn OFF the power supply and recconnect the reactor.
Is the reactor short-circuited?
Yes
Replace the outdoor power P.C. board.
OBH790D
No
No
on
No
No
-
on the
No
on the
No
Check the power supply cable.
Yes
Replace the outdoor control P.C. board.
No
Check the power supply and correct them.
Replace the inverter P.C. board.
Replace the reactor.
Replace the inverter P.C. board.
Check the connected wire between
the inverter P.C. board and outdoor
display P.C. board and correct it.
Replace the inverter P.C. board.
Replace the reactor.
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