LG 42LN54XX / 42LN540S / 42LN540V / 42LN541V / 42LN542V (CHASSIS:LD31B / LD36B) Service Manual ▷ View online
Standard Repair Process Detail Technical Manual
Inverter B+ 24V measuring method
A. Video error_No video/Normal audio
A2
Established
date
Revised
date
Error
symptom
Content
LCD TV
Measure DC
93.2~118.5V
applying to Module from Power Board.
Output
93.2~118.5V
from Power Board -> supply to Module.
Check Pin contacting statement and connection statement.
<ALL MODELS>
2013. 01 .09
Standard Repair Process Detail Technical Manual
Check White Balance value
A. Video error_No video/Normal audio
<ALL MODELS>
A3
Established
date
Revised
date
Error
symptom
Content
LCD TV
Entry method
1. Press the ADJ button on the remote controller for adjustment.
2. Enter into White Balance of item 7.
3. After recording the R, G, B (GAIN, Cut) value of Color Temp (Cool/Medium/Warm), re-
enter the value after replacing the MAIN BOARD.
2013. 01 .09
Standard Repair Process Detail Technical Manual
Power Board voltage measuring method
A. Video error_No video/ Audio
A4
Established
date
Revised
date
Error
symptom
Content
LCD TV
Check the DC 24V, 12V, 3.5V.
18 Pin
(Power Board ↔ Main Board) - Common
1
Power on
2
DRV ON
3
3.5V
4
PDIM#1
5
3.5V
6
PDIM#2
7
GND
8
GND
9
24V
10
24V
11
GND
12
GND
13
12V
14
12V
15
12V
16
N.C
17
GND
18
GND
Edge LED
2013. 01 .09
MENU => Press red key Remote controller=>signal test
=> Select channel
When the signal is strong, use the
attenuator (-10dB, -15dB, -20dB etc.)
Standard Repair Process Detail Technical Manual
TUNER input signal strength checking method
A. Video error_Video error, video lag/stop
<ALL MODELS>
A5
Established
date
Revised
date
Error
symptom
Content
LCD TV
2013. 01 .09
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