Check Of Indoor Electronic Control P.c. Board - Mitsubishi Electric MS-C18TV-E1 WH 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.
Does the unit operate with the remote controller?
Does the OPERATION INDICATORE lamp light up
by pressing the EMERGENCY OPERATION switch?
Yes
Replace the vane
motor.
Turn OFF the
power supply.
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 / or outdoor fan motor doesn't operate.
MS-C18TV
No
Turn OFF the
power supply.
Yes
No
Be sure to check both fuse
and varistor in any case.
No
Yes
Yes
Check the outdoor
wiring, the outdoor
fan motor and
compressor.
Yes
Check the conti-
nuity of indoor
and outdoor unit
connection.
1
3
Replace the fuse.
Yes
No
Is fuse(F11) blown?
No
Is varistor(NR11) burnt?
Yes
Replace the varistor.
Turn ON the power supply.
Press the EMERGENCY OPERA-
TION switch.
3-minute time delay works.
Test run operation operates for 30
minutes.
Check the voltage to terminal block
of outdoor unit.
Is there 230V AC to terminal block
between 2 - N ?
No
Check the voltage to terminal block
of indoor unit.
Is there 230V AC to terminal block
between 2 - N ?
No
Replace the indoor electronic con-
trol P.C. board.
33
1
2
F12
CN201
N
Terminal
block
1.Pull out the power
supply cord.
2.Measure the resistance
1
between CN201 on
the indoor electronic
control P.C. board
N
and on the terminal
block with a tester.
Replace the
indoor electronic
control P.C. board.
Yes
Is resistance approx. 0"?
No (∞)
Replace the fuse (F12)