LG 55LW9800-TA (CHASSIS:LB12D) Service Manual ▷ View online
Checking method
1. Press the MENU button on the remote controller
2. Select the AUDIO function of the Menu
3. Select TV Speaker from Off to On
Standard Repair Process Detail Technical Manual
Checking method in menu when there is no audio
C. Audio error_No audio/Normal video
<ALL MODELS>
A24
Established
date
Revised
date
Error
symptom
Content
LCD TV
A24
2010. 12 .14
Checking order when there is no audio
① Check the contact condition of or 24V connector of Main Board
② Measure the 24V input voltage supplied from Power Board
(If there is no input voltage, remove and check the connector)
③ Connect the tester RX1 to the speaker terminal and if you hear the Chik Chik sound when you touch the
GND and output terminal, the speaker is normal.
GND and output terminal, the speaker is normal.
Standard Repair Process Detail Technical Manual
Voltage and speaker checking method
when there is no audio
when there is no audio
C. Audio error_No audio/Normal video
<ALL MODELS>
A25
Established
date
Revised
date
Error
symptom
Content
LCD TV
A25
①
②
③
24 Pin
(Power Board ↔ Main Board) -
공통
SMAW200-H24S (YEONHO)
1
Power on
2
20V (24V)
3
20V (24V)
4
20V (24V)
5
GND
6
GND
7
GND
8
GND
9
3.5V
10
3.5V
11
3.5V
12
3.5V
13
GND
14
GND
15
GND
16
GND
17
12V
18
Inverter On/off
19
12V
20
Lamp : A-Dim
LED : N.C
21
12V
22
PWM Dim #1
23
N.C
•
Lamp SCANNING
Model
: PWM Dim #2
24
Error-out
②
2010. 12 .14
Checking order
1, 2. Check IR cable condition between IR & Main board.
3. Check the st-by 3.3V on the terminal 6.
4. When checking the Pre-Amp when the power is in ON condition, it is normal when the
3. Check the st-by 3.3V on the terminal 6.
4. When checking the Pre-Amp when the power is in ON condition, it is normal when the
Analog Tester needle moves slowly, and defective when it does not move at all.
Standard Repair Process Detail Technical Manual
Remote controller operation checking method
D. Function error_ No response in remote controller,
key error
<ALL MODELS>
A27
Established
date
Revised
date
Error
symptom
Content
LCD TV
A27
P8200
1
SCL
2
SDA
3
GND
4
KEY1
5
KEY2
6
St 3.5V
7
GND
8
LED_B/logo_PWM
9
IR
10
GND
11
3.3V_Normal
12
LED_R/BUZZ
13
GND
14
ST_SCL
15
ST_SDA
①
②
③
④
2010. 12 .14
Standard Repair Process Detail Technical Manual
Sequence of the Vcom adjustment
D. VCOM Adjustment
1. Case
■ LCD module change
■ T-Con board change
■ T-Con board change
2. Equipment
■ Service Remote controller
3. Adjust sequence
■ Press the ‘adj’ key
■ select V-COM
■ As pushing the right or the left button on the remote controller, And find the V-COM value Which is no or
minimized the Flicker.
(If there is no flicker at default value, Press the exit key and finish the VCOM adjustment.)
■ Push the OK key to store the value. Then the message “Saving OK” is pop.
■ Press the exit key to finish V-COM adjustment.
■ select V-COM
■ As pushing the right or the left button on the remote controller, And find the V-COM value Which is no or
minimized the Flicker.
(If there is no flicker at default value, Press the exit key and finish the VCOM adjustment.)
■ Push the OK key to store the value. Then the message “Saving OK” is pop.
■ Press the exit key to finish V-COM adjustment.
A28
Established
date
Revised
date
Error
symptom
Content
LCD TV
A28
2010. 12 .14