Mitsubishi Electronics MUZ-FD09NA service manual Check of LEV Expansion valve

Heating/Cooling does not work sufficiently.

K Check of LEV (Expansion valve)

Turn ON the power supply. <Preparation of the remote controller>

While pressing both OPERATION SELECT button and TOO COOL button on the remote controller at the same time, press RESET button.

First, release RESET button.

And release the other two buttons after all LCD except the set temperature in operation display ection of the remote controller is displayed after 3 seconds.

Press OPERATE/STOP (ON/OFF) button of the remote controller (the set temperature is displayed) with the remote controller headed towards the indoor unit. 1

Expansion valve operates in full-opening direction.

Do you hear the expansion valve "click,
click·······"?
			OK.
Do you feel the expansion valve vibrate		Yes
on touching it ?
	No

1. Regardless of normal or abnormal condition, a short beep is emitted once the signal is received.

Is LEV coil properly fixed to the expansion valve?

Yes

Does the resistance of LEV coil have the characteristics? (Refer to 10-4.)

No

Replace the LEV coil.

No

Yes

Properly fix the LEV coil to the expansion valve.

Measure each voltage between connector pins of CN724 on the inverter P.C. board. 1.Pin(-) — Pin(+)

2.Pin(-) — Pin(+) 3.Pin(-) — Pin(+) 4.Pin(-) — Pin(+)

Is there about 3 ~ 5 VAC between each? NOTE: Measure the voltage by an analog

tester.

Yes

Replace the expansion valve.

Replace the inverter P.C. No board.

NOTE : After check of LEV, do the undermentioned operations.

1.Turn OFF the power supply and turn ON it again.

2.Press RESET button on the remote controller.

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