LG 75SM9400PTA Service Manual page 77

Standard Repair Process Detail Technical Manual
symptom
Content
Checking order when there is no audio
1. Check the contact condition of or 20V connector of Main Board.
2. Measure the 20V 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.
Error
C. Audio error_No audio/Normal video
Voltage and speaker checking method
when there is no audio
②
Established
date
Revised
date
①
A13
③
1 SPK_R-FT 5 SPK_R-CT
2 SPK_R+FT 6 SPK_R+CT
3 SPK_ L-FT 7 SPK_ L-CT
4 SPK_ L+FT 8 SPK_ L+CT
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A13