LG LRE30451 Service page 48

FAILURE MODE FLOW CHART
No display (No power)
1
Is it 120V AC?
Yes
Disconnect power
Check the power transformer (Refer to the below)
Fig.1
Side Lead Color
P black ~ white
S1 yellow ~ blue ~ yellow
S2 green ~ green
S3 red ~ red
No
Primary
Secondary
DCR(Ω)
25 ~ 28
4.2 ~ 4.9
1.5 ~ 1.8
1.1 ~ 1.3
Normal?
Yes
Replace the Main PCB(009A)
END
6-4
Check the harness of between L1~N
Yes
Replace the defective harness
S3 S2 S1
measure LVT coil resistance
(Normal: approximately Fig.1)
No
Normal?
No
P
Replace the power transformer
END