Mitsubishi Electric MSZ-A09RV-E1 Service Manual page 52

(How to check power supply and others)
L
Check of power supply.
Inverter does not work.
Disconnect connector between compressor and IPM.
Turn power on to indoor unit and press Emergency
operation switch.
3 minutes after power-on, is there voltage of approx.
220-240V AC between outdoor terminal block 2and N?
Is there approx. 370V DC between both ends of smoothing
capacitor (C62) on electronic control P.C. board?
Dose LED light up or flash on outdoor electronic control
P.C. board.?
Dose LED flash on outdoor electronic control P.C. board.?
Repair according to the LED indication.
M
Check of thermal fuse
Unplug the power cord.
N
Check of electronic control P.C. board
Not become cooling/heating. (Not increase speed of compressor rotation)
Check the connecting CN911 in the relay P.C. board
and CN726 in the electronic control P.C. board.
Turn on power supply to indoor unit, and
press Emergency operation switch.
Does the outdoor unit fan operate
nomally?
Check LED indication in the electronic
control P.C. board.
Converter protect
suspension
Yes
Yes
Yes
Flash
Is resistance ° between connector CN 201 1 on indoor
electronic control P.C. board and terminal block N?
No
Yes
Except for 8 times flashing
8 times flashing
· Press Emergency operation switch again to check if
No
Relay 52C works.
· Mis-wiring of in-out connection or disconnection.
· Indoor electronic control P.C. board defect.
· Main circuit
· Reactor
No
· Noise filter P.C. board
· Connection of connector
No
Outdoor electronic control P.C. board defect.
Light up
Normal
No
Normal
Check the outdoor fan motor
(refer to page 46)
Check the applicable parts by
LED indication
Replace electronic control P.C. board
52
defective
370V DC
(-)
C62
LED
(+)
Electronic control P.C. board
Yes
Replace thermal fuse.
Indoor electronic
control P.C. board.
CN201