LG ARNU Series, Service Manual

Page: 120 / 226

120 Trouble Shooting Guide
Checking Method for Key Components
• LEV failure check method
Failure mode Diagnosis Repair process Unit
Microcomputer
Driving circuit
failure 1.Disconnect the LEV connector form control board and
connect testing LED
2. Main power ON, pulse signal is out from LEV for 17 sec.
If LEDs do not turn on, or are in on state continuously,
then driving circuit is abnormal
Check and replace
Indoor unit control
board Indoor
unit
LEV locking 1.If LEV is locked, in no load state, the driving motor rotate,
and clicking sound always occurs Replace LEV Indoor
/ Outdoor
unit
LEV Motor coil
short or
misconnection 1. Check the resistance between coil terminal
(red-white, red-yellow, red-orange, red-blue)
2. If the estimated resistance value is in 52
±
3
Ω
then the LEV is normal
Replace LEV Outdoor
unit
1. Check the resistance between coil terminal
(brown-white, brown-yellow, brown-orange, brown-blue)
2. If the estimated resistance value is in 150
±
10
Ω
then the LEV is normal
Replace LEV Indoor
unit
1. Operate indoor unit with FAN mode and operate another
indoor unit with COOLING mode
2. Check indoor unit(FAN mode) liquid pipe temperature
(from operation monitor of outdoor unit control board)
3. When fan rotate and LEV is fully closed, if there is any
leakage, then the temperature is down
If estimated temperature is very low in comparison with
suction temperature which is displayed at remote
controller then the valve is not fully closed
If the amount of
leakage is much,
Replace LEV Indoor
unit Full closing
(valve leakage)
1K LED