LG LRE30451SW Service Manual page 42

FAILURE MODE FLOW CHART
No display (No power)
1
Is it 120V AC?
Yes
Disconnect power
Check the power transformer (Refer to the below)
Secondary
Fig.1
Side Lead Color
P black ~ white
S1 yellow ~ yellow
S2 red ~ red
No
Primary
DCR(Ω)
25 ~ 28
1.0 ~ 1.3
measure LVT coil resistance
1.8 ~ 2.1
(Normal: approximately Fig1)
Normal?
Yes
Replace the Main PCB(002A)
END
6-3
Check the harness of between L1~N
Yes
Replace the defective harness
S2 S1
No
Replace the power transformer
Normal?
No
P
END