LG 55LD650 (CHASSIS:LT03B) Service Manual ▷ View online
Checking order when there is no audio
① Check the contact condition of 20V 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.
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
Edge LED 32/42/47”
Error-out
24
NC
23
LE : PWM Dim #1
IOP : NC
22
12V
21
LE : NC
IOP : PWM Dim #1
20
12V
19
Inverter ON
18
12V
17
NC
16
GND
15
GND
14
GND
13
3.5V
12
3.5V
11
3.5V
10
3.5V
9
GND
8
GND
7
GND
6
GND
5
24V
4
24V
3
24V
(IOP & Edge 55”)
20V (
Edge 42/47
)
2
Power
on
1
Pin layout (24P)
①
②
③
2010. 2 .19
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 Analog
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
1
2
LED_R
12
Normal 3.3V
11
GND
10
IR
9
LED_B
8
GND
7
St 3.3V
6
KEY2
5
KEY1
4
GND
3
SDA
2
SCL
1
P8200
3
4
2010. 2 .19
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
2010. 2 .19
A28
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
2010. 2 .19
A28