Established
date
Standard Repair Process
Revised date
1/1
0
LED TV
Error
symptom
A
1
.
Power Supply Trouble
No power
20 1
6
.
12
.
31
1
ǃ
ǃ
Power Supply Trouble
Check Pin1
ǃ
2 of CNB2 for 12V
Check if the power
board is OK?
N
N
N
Check power on the TV board.
Repair the power board.
Y
Check U2 for 5V_STB , UL1 for
3.3V_STB and UD1 for +1.15V_STB
Y
Y
Repair the abnormal circuit :
1.5V_STB—check U2
2. 3.3V_STB—check UL1
3.+1.15V–- check UD1
and peripheral components
N
Power on , check QM32 for
5V_M,UL1 for VCC_DDR
Y
Repair the abnormal circuit :
1.. 5V_M
heck power supply ,and
QM32 circuit
2..
CC_DDR–- check UL1
OK
Copyright
ⓒ
2017 LG Electronics Inc. All rights reserved.
Only training and service purposes.
Summary of Contents for 28LJ400B
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