Mitsubishi Electric MUZ-FS06NAH-U1 Service Manual page 38

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 left 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 (–)
(MUZ-FS06/09/12)/294 - 370 V DC
between IC700 (P) and (N)
(MUZ-FS15/18) on the inverter P.C.
board? (Refer to 10-6.1.)
No
Check the electric parts in main circuit.
OBH873A
Rectify indoor/outdoor
connecting wire.
Yes
Is there voltage 208/230 V DC
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.
294 -370 V DC
38
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-FS06/09/12
IC932
P
Inverter P.C board
N
(Solder side)
IC700
MUZ-FS15/18