Obh629 - Mitsubishi Electric MUZ-SF25VE-E1 Service Manual

K Check of LEV (Expansion valve)
Turn ON the power supply.
<Preparation of the remote controller>
While pressing both OPERATION SELECT button
and TEMP 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. Confi rm that the indicators on the LCD screen
shown in the right fi gure 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 fi xed to
the expansion valve?
Yes
Does the resistance of LEV
coil have the characteristics?
(Refer to 11-4.)
No
Replace the LEV coil.
NOTE: After check of LEV, do the undermentioned operations.
1. Turn OFF the power supply and turn it ON again.
2. Press RESET button on the remote controller.

OBH629

OK
Yes
Properly fi x 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 VAC between each?
NOTE: Measure the voltage by an analog
tester.
Replace the expansion valve.
1. Regardless of normal or abnormal condition, a short beep
is emitted once the signal is received.
Yes
39
Replace the inverter P.C.
No board.