Read LG 55LA7900 (CHASSIS:LA34D) Service Manual online
Checking order when there
is no audio
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
A25
Established
date
Revised
date
Error
symptom
Content
LCD TV
A25
①
③
2011. 12 .14
60LA86 : 18P
55LA86/55LA79 : 24P
24 Pin
(Power Board ↔ Main Board)
SMAW200-H24S
1
Power on
2
Inverter On/off
3
3.5V
4
PWM Dim #1
5
3.5V
6
PWM Dim #2
7
GND
8
GND
9
24V
10
24V
11
GND
12
GND
13
12V
14
12V
15
12V
16
24V
17
GND
18
GND
19
GND
20
GND
21
GND
22
L/DIMO_VS
23
L/DIM0_MOSI
24
L/DIM0_SCLK
<ALL MODELS>
②
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