LG 39LN549C (CHASSIS:LA3AA) Service Manual ▷ View online
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2. Digital/Analog TV Video
Check RF Cable & Signal
Check Tuner 3.3V Power
L1003
Replace L1003
Check Tuner 1.8V Power
IC1001 2 pin : 1.8V
Check IF_P/N Signal
TU1002 10/11 Pin
Replace IC1001
Check Mstar LVDS Output
Replace Mstar(IC101) or Main Board.
ok
ok
ok
ok
No
No
No
No
Bad Tuner. Replace Tuner.
3. AV Video
Check input signal format.
Is it supported?
Check AV Cable for damage
for damage or open conductor
Check JK701, CVBS Signal Line
R246
ok
ok
ok
No
Replace Jack
ok
Check CVBS_DET Signal
R705
Replace R705
No
Check Mstar LVDS Output
Replace Mstar(IC101) or Main Board.
No
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4. RGB Video
Check input signal format.
Is it supported?
Check RGB Cable
for damage or open conductor.
Check JK705
R/G/B signal Line
ok
ok
ok
No
Replace Jack
Check RGB_DET Signal
Replace R1732
No
Check Mstar LVDS Output
Replace Mstar(IC101) or Main Board.
ok
No
5. HDMI Video
Check input signal format.
Is it supported?
Check HDMI Cable conductors
for damage or open conductor.
Check EDID Downlaod
ok
ok
ok
No
Replace the defective IC or re-download EDID data
Check HDMI Signal
Check other set
If no problem, check signal line
ok
No
Check Mstar LVDS Output
Replace Mstar(IC101) or Main Board.
ok
No
Replace Main Board
No
Check HDMI_DET (HPD)
No
Replace HDMI1 R802, R805, Q801
HDMI2 R804, R805, Q802
HDMI3 R815, R817, Q804
Check HDMI I2C Signal
ok
No
Replace D801. D802
Check JK801, JK802,JK803
No
Replace Jack
ok
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6. All Source Audio
Check the TV Speaker Menu
(Menu -> Audio -> TV Speaker)
On
ok
ok
Replace C535, C537, C538, R516, R517
Check Connector & P501
Replace connector
if found to be damaged.
ok
No
Check speaker resistance
and connector damage.
Replace speaker.
ok
No
Off
Toggle the Menu
Check AMP IC(IC501) Power
24V, 3.3V
No
Replace Amp IC(IC501)
Check Output Signal P501
1, 2, 3, 4 pin.
No
Check Mstar AUDIO_MASTER_CLK
R148
No
Replace Mstar(IC101) or Main Board.
ok
Check AMP I2C Line
R503, R504
No
Check signal line. Or replace Mstar(IC101)
Replace Audio AMP IC(IC501)
Check signal line, L505, L506
ok
No
7. Digital/Analog TV Audio
Check RF Cable & Signal
Follow procedure
‘7. All source audio’
trouble shooting guide.
ok
Check Tuner 3.3V Power
L1003
Replace L1003
Check Tuner 1.8V Power
IC1001 2 pin : 1.8V
Check IF_P/N Signal
TU1002 6 Pin
Replace IC1001
ok
ok
ok
No
No
No
Bad Tuner. Replace Tuner.
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8. AV/RGB Audio
Check AV Cable for damage
for damage or open conductor
Check JK701 Signal Line
R706,R707
ok
ok
No
Replace Jack
Follow procedure
‘7. All source audio’
trouble shooting guide.
ok
ok
Check Output Signal JK902
4,5 pin.
Replace Phone Jack(JK902)
ok
No
Check JK902
Replace Phone Jack
if found to be damaged.
ok
No
Check External Speaker
Replace External speaker.
ok
No
Check AMP IC(IC901) Power 24V
L902
No
Replace L902
Check AMP IC(IC1800) Output
2,12,14, 24 Pin
No
replace AMP IC(IC901)
Check Mstar External AUDIO output
R201, R202
No
Replace Mstar(IC101) or Main Board.
ok
Check AMP IC(IC901) Mute High
R1924, 4pin
No
Check signal line. Or replace Mstar(IC101)
9. External Speaker Out
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