LG 55LEX8-SA (CHASSIS:LJ03S) Service Manual ▷ View online
3. Trouble shooting - No video (Analog TV video)
Check RF Cable & Signal
Check Tuner 3.3V Power
L701
Replace L701
Check Tuner 1.2V Power
IC700 2 pin : 1.26V
Check CVBS Signal
TU701 14 Pin
Replace IC700.
Check Tuner 5V Power
L700
Check IC8003
ok
ok
ok
ok
ok
No
No
No
No
No
Replace IC8003
No
Bad Tuner. Replace Tuner.
Replace L8007
ok
Check BCM LVDS Output
Replace BCM( IC900) or Main Board.
4. Trouble shooting - No video (AV)
Check input signal format.
Is it supported?
Check AV Cable for damage
for damage or open conductor
Check JK2501 CVBS Signal Line
Rear AV : R2504, R904
ok
ok
ok
No
Replace Jack
ok
Check CVBS_DET Signal
• Rear AV Detect : R2512
Replace R2512
No
No
Check BCM LVDS Output
Replace BCM( IC900)
or Main Board.
Check input signal format.
Is it supported?
Check Component Cable
for damage or open conductor.
Check JK2500
Y/PB/PR signal Line
ok
ok
ok
No
Replace Jack
Check COMP_DET Signal
Replace R2505
No
ok
No
Check BCM LVDS Output
Replace BCM( IC900) or Main Board.
5. Trouble shooting - No video (Component)
Check input signal format.
Is it supported?
Check RGB Cable conductors
for damage or open conductor
Check EDID & EEPROM
IC3502 I2C Signal R3512,
R3511, R970, R973, R974(SDA,SCL)
Check JK3202(in Sub B/D #2)
H/V_Sync/R/G/B Signal Line
p3304 pin 41, 38, 35, 33 ,32
ok
ok
ok
No
No
Re-download EDID data or Replace the defective IC
ok
Replace Jack or P3304
Check DSUB_DET
P3304 pin 21
Replace Jack or P3304
No
ok
No
Check BCM LVDS Output
Replace BCM( IC900) or Main Board.
6. Trouble shooting - No video (RGB-PC)
Check Sub Board-Main Board
FPCB Cable for damage
ok
No
Replace FPCB Cable
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