Check Of Indoor Electronic Control P.c. Board; Check Of Outdoor Unit - Mitsubishi Electric MS-18NV Service Manual

Check of indoor electronic control P.C. board

C
The unit doesn't operate with the remote controller.
Also, the OPERATION INDICATOR lamp doesn't light up by pressing the EMERGENCY OPERATION switch.
Check the both "parts side"and "pattern side" of
indoor electronic control P.C. board visually.
Turn OFF the power supply.
Remove indoor fan motor connector CN211 and vane
motor connector CN151 from the indoor electronic
control P.C. board and turn ON the power supply.
The unit doesn't operate with the remote controller.
Also, the Operation Indicator lamp doesn't light up
by pressing the EMERGENCY OPERATION switch.
No
Replace the vane
motor.
Is winding
resistance of
vane motor 0 "?
Be sure to check both fresistance.
Is winding
resistance of
fan motor 0 "?
Replace the fan
motor .

Check of outdoor unit

D
Compressor and outdoor fan do not operate.(Only indoor fan operates.)
Check the outdoor
wiring, the outdoor
fan motor and
compressor.
Check the
continuity of
indoor and
outdoor unit
Yes
Yes
No
Be sure to check both fuse
and varistor in any case.
No
Yes
Press the EMERGENCY
OPERATION switch.
3-minute time delay works.
Test run operation operates for 30
minutes.
Check the voltage to terminal block
Yes
of outdoor unit.
Is there 220-240V AC to terminal
block between
Check the voltage to terminal block
Yes
of indoor unit.
Is there 220-240V AC to terminal
block between 2 - N ?
Replace the indoor electronic
control P.C. board.
1
3
Replace the fuse.
Yes
No
Is fuse(F11) blown?
No
Is varistor(NR11) burnt?
Yes
Replace the varistor.
Start
2 - N ?
No
No
22
1
2
F12
CN201
L
N
Terminal
block
1.Pull out the power
supply cord.
2.Measure resistance
1
between CN201 on
the indoor electronic
control P.C. board
N
and on the terminal
block with a tester.
Trouble of the
indoor electronic
control P.C. board.
Yes
Is resistance 0"?
No
Trouble of fuse (F12)