LG 55LA6650 (CHASSIS:LA33B) Service Manual ▷ View online
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Checking method
1. Press the MENU button on the remote controller
2. Select the AUDIO function of the Menu
3. Select TV Speaker Or Other
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
2012. 11 .30
24 Pin
(Power Board ↔ Main Board) -
공통
SMAW200-H18S1 (YEONHO)
1
Power on
2
INV_ON
3
3.5V
4
PDIM #1(PWM Dim #1)
5
3.5V
6
PDIM #2(PWM Dim #2)
7
GND
8
GND
9
24V
10
24V
11
GND
12
GND
13
12V
14
12V
15
12V
16
12V
17
GND
18
GND
19
GND
20
GND
21
GND
22
L/DIM0_VS
23
L/DIM0_MOSI
24
L/DIM0_SCLK
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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.
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
①
②
③
②
2012. 11 .30
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Checking order
1, 2. Check IR cable condition between IR & Main board.
3. Check the st-by 3.3V on the terminal 4.
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 4.
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
P4102
1
GND
2
Key1
3
Key2
4
+3.5V_ST
5
GND
6
LOGO / LED_R
7
IR
8
GND
9
EYE_SCL
10
EYE_SDA
①
②
③
④
2012. 11 .30
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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
2012. 11 .30