Mitsubishi Electric MUZ-JP09WA-U1 Service Manual page 32

J Check of power supply
Disconnect the connector between the
compressor and the power module (IC700).
Turn ON power supply and press
EMERGENCY OPERATION switch.
Does the upper lamp of the
OPERATION INDICATOR lamp on
the indoor unit light up?
Yes
Is there bus-bar voltage 260 - 370
V DC between DB61 (+) and DB61
(–) on the inverter P.C. board?
(Refer to 10-6.1.)
No
Check the electric parts in main circuit.
260 - 370 V DC
DB61
Inverter P.C. board
(Solder side)
OBH821A
Rectify indoor/outdoor
connecting wire.
No
Is there voltage 115 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 10-6.1.)
Yes
If lights up, OK.
If blinks, refer to 10-3.
32
Replace the indoor
electronic control P.C.
Yes
board.
Replace the inverter
No P.C. board.