Check Of Indoor Electronic Control P.c. Board - Mitsubishi Electric MSH09TW Service Manual

The unit doesn't operate with the remote controller.
Also, the OPERATION INDICATOR lamp doesn't light up by pressing the EMERGENCY OPERATION switch.
C C Check of indoor electronic control P.C. board
Check the both "parts side" and "pattern
side" of indoor electronic control P.C.
board visually.
Turn OFF the power supply.
Disconnect indoor fan motor connector CN211(MSH09
only) 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 or
the OPERATION INDICATOR lamp light up
by pressing the EMERGENCY OPERATION switch?
Yes
Turn OFF the
Replace the vane
power supply.
motor.
Is winding
resistance of
vane motor 0 "?
Be sure to check both resistances.
Is winding
resistance of
fan motor 0 "?
Replace the fan
motor.
No
Turn OFF the
power supply.
Yes
No
Be sure to check both fuse
and varistor in any case.
Is varistor (NR11) burnt?
No
Yes
Replace the fuse.
Yes
No
Is fuse (F11) blown?
No
Yes
Replace the varistor.
85
Replace the indoor
electronic control
P.C. board.