Mitsubishi Electric Mr.Slim MUZ-FE09NA Service Manual page 28

J Check of power supply
MUZ-FE09NA MUZ-FE12NA
Disconnect the connector (CN61)
between compressor and intelligent
power module.
Turn ON power supply and press
EMERGENCY OPERATION switch.
Does POWER lamp on the indoor
unit light up?
Yes
Is there bus-bar voltage 260-325
VDC between DB61 (+) and DB61
(–) on the inverter P.C. board?
(Refer to 10-6.1.)
No
Check the electric parts in main circuit.
Rectify indoor/outdoor
connecting wire.
Yes
Is there voltage 208/230 VAC
between the indoor terminal
No
block S1 and S2?
Does LED on the inverter P.C.
board light up or fl ash? (Refer
Yes
to 10-6.1.)
Yes
If light up, OK.
If fl ash, refer to 10-3.
28
Replace the indoor
electronic control P.C.
No
board.
Replace the inverter
No
P.C. board.
260-325VDC
DB61
Inverter P.C. board
(Solder side)