Logitech OB450 REVISED EDITION-B, MSZ-A09NA service manual Indoor electronic control P.C.Board

C Check of indoor electronic control P.C. board and indoor fan motor

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 OPERATION INDICATOR lamp light up by pressing EMERGENCY OPERATION switch?

No

Turn OFF the power supply.

Check both “parts side” and “pattern side” of the indoor electronic control P.C. board visually.

Measure the resistance between
	Short/open circuit:
CN211 and of the indoor fan motor
	Replace the indoor fan motor.
connector.

Yes

Measure the resistance of the horizon-	Short/open circuit:
tal vane motor coil.	Replace the horizontal vane motor and the
(Refer to 8-5.)	indoor electronic control P.C. board.

Replace the indoor electronic control P.C. board.

Yes

Are the varistor (NR11) burnt and the fuse (F11)

blown?No

Be sure to check both the fuse and the varistor in any case.

Is the fuse (F11) blown

only?No

Yes

Measure the resistance between

(+)and (-) of the indoor fan motor connector (to CN211 on the indoor electronic control P.C. board). 1, 2

Is the resistance 1 MΩ

or more? No

Yes

1. The fan motor connector's lead wire is red, whereas is black.

2. Connect "+" of the tester to fan motor connector's lead wire, and "-" to lead wire, otherwise the resistance can- not be measured properly.

Replace indoor electronic control P.C. board and the indoor fan motor.

Replace indoor electronic control P.C. board.

Measure the resistance of cement resistor (R111) on the indoor elec-

tronic control P.C. board.

Is the resistance approx.
4 Ω?		No
	Yes

Replace the indoor electronic control P.C. board and the indoor fan motor.

Indoor electronic control P.C.Board

Varistor(NR11)

Fuse(F11)

CN211

Replace the indoor electronic control P.C. board.

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