Mitsubishi Electric MUZ-FE09NA Service Manual page 32

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.
Hold down the other two buttons for another 3 sec-
onds. Make sure that the indicators on the LCD
screen shown in the right figure are all displayed.
Then release the buttons.
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·······"?
Do you feel the expansion valve vibrate
on touching it ?
No
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.
NOTE: After check of LEV, take the following steps.
1. Turn OFF the power supply and turn ON it again.
2. Press RESET button on the remote controller.
OBH543G
OK
Yes
Properly fix the LEV coil to the expansion valve.
No
Measure each voltage between connector
pins of CN724 on the inverter P.C. board.
1. Pin (-) — Pin (+)
2. Pin (-) — Pin (+)
3. Pin (-) — Pin (+)
Yes
4. Pin (-) — Pin (+)
Is there about 3 ~ 5 V AC between each?
NOTE: Measure the voltage by an analog
tester.
Replace the expansion valve.
MSZ-FE09NA
MSZ-FE12NA
*1. Regardless of normal or abnormal condition, a short beep is
emitted once the signal is received.
Yes
32
MSZ-FE18NA
Replace the inverter P.C.
No board.