A6 Power supply Trouble 2
No power
(VWDEOLVKHG
GDWH
5HYLVHGGDWH
0
/('79
(UURU
V\PSWRP
Standard Repair Process
6
12
31
Check EMI open or L N short
Go to
check
Main
board
function
Check if FB 1 Open
Check the power
components
damage or not
Check the rectifier
Check if output short
Check if RB100,
RB101,RB102
open
Non output, IR indicator light slake
Check if 12V
ǃ
19V
˄
24V/
32V/50V
˅
output normal
Check if EB1 voltage
about
¥
2Vac
Y
Check if UB101 PIN5
voltage is about 15V
Change damaged
components
Change short
components
Change damage
resistors
Change
UB101
9
ǃ
Power Supply Trouble 2
N
Y
Y
Y
Y
Y
Y
N
N
N
N
N
Copyright
ⓒ
2017 LG Electronics Inc. All rights reserved.
Only training and service purposes.
Summary of Contents for 28LJ400B
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