LG 55LV3700 (CHASSIS:LA12B) Service Manual ▷ View online
Check input signal format.
Is it supported?
Check RGB Cable conductors
for damage or open conductor
Check EDID & EEPROM
IC3802 I2C Signal R3811, R3812(SDA,SCL)
Check P3801
H/V_Sync/R/G/B Signal Line
L3806/7/8
ok
ok
ok
No
No
Re-download EDID data or Replace the defective IC
ok
Replace Jack
Check DSUB_DET
Replace R3815
No
ok
No
Check BCM LVDS Output
Replace BCM( IC101).
6. Trouble shooting - No video (RGB-PC)
7. Trouble shooting - No video (HDMI)
Check input signal format.
Is it supported?
Check HDMI Cable conductors
for damage or open conductor.
for damage or open conductor.
Check HDMI Switch
IC701 video Signal and I2C line
Check JK70 1 / 2 / 3 / 4
ok
ok
ok
No
No
Replace Coil
ok
Replace Jack
Check HDMI Signal output
of HDMI Switch (IC701)
Replace the defective IC.
No
Check L2103(+3.3V)
Replace the defective IC.
No
OK
ok
No
Check BCM LVDS Output
Replace BCM( IC101) or Main Board.
8. Trouble shooting - No Audio (all audio source)
Check the TV Speaker Menu
(Menu -> Sound -> TV Speaker)
On
ok
ok
Check Output Signal P1702
1, 2, 3, 4 pin.
Replace Audio AMP IC(IC1702)
ok
No
Check Connector & P1702
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(IC1702) Power
*24V, 3.3V
No
Check Regulator L1709,L1710,L1711
Check Mstar I2S Output
R1754,5,6
No
Check signal line.
Or replace BCM( IC101)
Check AUDIO_MASTER_CLK
R1753
No
Replace BCM( IC101) or Main Board.
ok
Check AMP I2C Line
R1710,1711
No
Check signal line.
Or replace BCM( IC101)
Check RF Cable & Signal
Check Tuner 3.3V Power
L2103
Replace L2103
Check Tuner 1.26V Power
IC2103 2 pin : 1.26V
Check IF_P/N Signal
TU2101 17,18 Pin
Replace IC2103
Check Tuner 5V Power
L2101,L2104
ok
ok
ok
ok
No
No
No
Bad Tuner. Replace Tuner.
Check IC507
No
Replace IC507
No
Replace L2101,2104
ok
9. Trouble shooting - No audio (Digital TV audio)
Follow procedure
‘8. All source audio’
trouble shooting guide.
ok
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