LG 28LN45 Series Service Manual page 16

2. No Picture
Module
Back Light On ?
Y
Check Panel power
P601(#27,28,29,30) 12V
IC802 Output 12V
Y
Check Panel clock
P601(#9,10)
Y
Check FFC Cable for damage
or open conductors.
Y
Replace T-con
Board or module
3. No Video - Digital TV
Check RF Cable
Y
1. Check Tuner(TU2602 #5) Power (3.3V)
2. Check IC803 Output voltage(3.3V)
Y
1. Check Tuner(TU2602 #7) Power (1.8V)
2. Check IC805 Output voltage(1.8V)
Y
Check Tuner(TU2602) I2C Signal
SCL(R2609), SDA(R2610)
Y
Check Tuner(TU2602)
Data, CLK, SYN, VAL
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Only for training and service purposes
N
Check WLED_ENABLE high
R131
Y
Check LED Driver output
(P1101 #1,2,3,4,5)
N
Replace IC802
N
Check IC101
Repair Main B/D
N
Replace Cable
N
N
N
N
- 16 -
N
Check IC101
Replace Main Scaler IC
N
Check LED Driver IC1101
Replace LED Driver IC
Replace IC803
Replace IC805
Check IC101
Replace Tuner(TU2602)
Recheck
LGE Internal Use Only