LG 49UF771V Service Manual page 103

Standard Repair Process Detail Technical Manual
Error symptom
Content
<LD53H, LD53J>
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.
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Only for training and service purposes
C. Audio error_No audio/Normal video
Voltage and speaker checking method
when there is no audio
1 PWR ON
3 P_DIM #1
5 3.5V
7 3.5V
9 GND
②
11 12V
13 12V
15 12V
17 GND
19 24V
21 24V
23 GND
Established
date
Revised
date
2 DVR_ON
4 PDIM #2
6 GND
8 3.5V
10 GND
12 12V
14 12V
①
16 GND
18 24V
20 24V
22 GND
24 NC
③
A21
1 SPK_R-
2 SPK_R+
3 SPK_L-
4 SPK_L+
LGE Internal Use Only
A21