Mitsubishi Electric MUZ-LN35VGHZ2-E1 Service Manual page 58

J Check of power supply
Disconnect the connector between the
compressor and the power module
(IC700). Turn ON power supply and
press the emergency operation switch.
Does POWER lamp on the indoor
unit light up?
Yes
Is there bus-bar voltage 260 - 370V
DC between DB61 (+) and DB61 (–)
(MUZ-LN25/35VGHZ/VGHZ2)/325 -
370 V DC between IC700 (P) and (N)
(MUZ-LN50VGHZ/VGHZ2) on the
inverter P.C. board? (Refer to 12-6.1.)
No
Check the electric parts in main circuit.
OBH768G
Rectify indoor/outdoor
connecting wire.
Yes
Is there voltage 230 V AC
between the indoor terminal
No
block S1 and S2?
Does LED on the inverter P.C.
board light up or blink?
Yes
(Refer to 12-6.1.)
Yes
If lights up, OK.
If blinks, refer to 12-3.
325 -370 V DC
325 -370 V DC
58
Replace the indoor
electronic control P.C.
No
board.
Replace the inverter
No P.C. board.
260 - 370 V DC
DB61
Inverter P.C. board
(Solder side)
MUZ-LN25/35VGHZ
MUZ-LN25/35VGHZ2
IC700
N
P
MUZ-LN50VGHZ
IC932
P
Inverter P.C board
N
(Solder side)
IC700
MUZ-LN50VGHZ2