LG 55LEX8-SA (CHASSIS:LJ03S) Service Manual ▷ View online
11. Trouble shooting - No Audio (all audio source)
Check the TV Speaker Menu
Menu -> Sound -> TV Speaker(or Sound Bar)
On
ok
ok
Check Output Signal P8800(or P2100)
1, 2, 3, 4 pin.
Replace Audio AMP IC(IC8801 or IC2100)
ok
No
Check Connector & P8800(or P2100)
Replace connector
if found to be damaged.
ok
No
Check speaker resistance
and connector damage.
Replace speaker(or sound bar).
ok
No
Off
Toggle the Menu
Check AMP IC(IC8801 or IC2100) Power
*24V, 3.3V, 1.8V.
No
Check Regulator IC8800
Check Mstar I2S Output
R8801, R8802, R8803
(or R2100,R2101,R2102)
No
Check signal line.
Or replace BCM( IC900)
Check AUDIO_MASTER_CLK
R8828(or R2119)
No
Replace BCM( IC900) or Main Board.
ok
Check AMP I2C Line
R8804, R8805(or R2103,R2104)
No
Check signal line.
Or replace BCM( IC900)
Check RF Cable & Signal
Check Tuner 3.3V Power
L701
Replace L701
Check Tuner 1.2V Power
IC700 2 pin : 1.26V
Check IF_P/N Signal
TU701 20,21 Pin
Replace IC700
Check Tuner 5V Power
L700
ok
ok
ok
ok
No
No
No
Bad Tuner. Replace Tuner.
Check IC8003
No
Replace IC8003
No
Replace L8007
ok
12. Trouble shooting - No audio (Digital TV audio)
Follow procedure
‘8. All source audio’
trouble shooting guide.
ok
Check RF Cable & Signal
Check Tuner 3.3V Power
L701
Replace L701
Check Tuner 1.2V Power
IC700 2 pin : 1.2V
Replace IC700.
ok
ok
No
No
Check Tuner 5V Power
L700
ok
Check IC8003
No
Replace IC8003
No
Replace L8007
ok
13. Trouble shooting - No audio (Analog TV audio)
Check TU_SIF path
Including Q701 TR buffer to LGE3549
ok
Check SIF Signal
TU701 13th Pin
ok
No
Bad Tuner. Replace Tuner.
Follow procedure
‘8. All source audio’
trouble shooting guide.
ok
No
Replace component
14. Trouble shooting - No audio (AV, Component)
Check AV Cable for damage
or open conductor
Check Audio OSD
(Audio OSD active or inactive mode?)
ok
ok
No (Inactive)
Check (AV : R2512 & R2506)
(Component : R2501&R2505)
Check Audio AMP Mute (pin25)
Replace JK2501
No
ok
Check Audio Master clock // AUD_LRCH
AUD_LRCK, AUD_SCK(AMP pin17,18,19)
Replace BCM3549
Check JK2501
No
ok
Check Audio AMP voltage
+1.8V_AMP, +3.3V_NORMAL,+24V_AMP
ok
ok
Check output L8804, L8805 &
AMP output
ok
Replace Audio AMP NTP7000
No
Follow procedure & refer to Audio signal block
Diagram
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