Mitsubishi Electric MS-18RV-E1 Service Manual page 57

Check of LEV (Expansion valve)
G
Cooling does not operate.
1 During pressing OPERATION SELECT button
on remote controller, press RESET button.
2 First, release RESET button.
(Confirm all displays of remote controller.)
3 Then release OPERATION SELECT button.
With remote controller set toward the indoor unit, press
OPERATE/ STOP(ON/ OFF) button and confirm one
beep tone.
LEV operates in full-opening
direction.
Do you hear LEV "click,
click·······"?
Do you touch LEV and feel
it vibrate?
No
Is LEV coil properly fixed to
the body?
Yes
Does the resistance of thermistor
have the characteristics?
No
Characteristics of LEV coil
Replace the
LEV coil.
Check of outdoor thermistor
H
Thermistors in the outdoor unit are abnormal.
w Disconnect the connectors CN662 from the deicer P.C. board. (Check the characteristics of each thermistor.)
Discharge temperature
thermistor(RT62)
Turn OFF the
power supply.
Ambient temperature
thermistor(RT63)
Yes
Ok
No
Properly fix LEV coil to
the body.
Yes
Replace the
DEICER P.C. board.
Resistance
LEV (CN724)
WHT–RED
RED–ORN
30.3 " ~ 37.0 "
YLW–BRN
BRN–BLU
<MS-30RV only>
Measure
resistance
between CN 662
1 and 2.
Does the resistance
of thermistor have the
characteristics on
page 60?
Measure
Replace the
resistance
thermistor.
between CN 662
3 and 4.
<MS-30RV only>
CLOCK
NOTE : After check of LEV, do the undermentioned operations.
1. Turn OFF the power supply of the unit and turn ON again.
2. Press the RESET button on the remote controller.
Connect CN662.
Turn ON the power
Yes
supply and press
the EMERGENCY
OPERATION
switch.
No
W1. It is thought defective contact of the connector.
57
1 During pressing OPERATION SELECT
button on remote controller, press
RESET button.
2 First, release RESET button.
(Confirm all displays of remote controller.)
3 Then release OPERATION SELECT button.
˚C
AMPM
AMPM
Replace the deicer P.C.
board.
No
Does the unit operate
10 minutes or more?
Yes
Ok W1.