Read LG 42LD550 (CHASSIS:LA02B) Service Manual online
6. RGB Video
Check input signal format.
Is it supported?
Check RGB Cable conductors
for damage or open conductor
Check EDID & EEPROM
IC8401 I2C Signal R8415,
R8416, R8417,R8421(SDA,SCL)
Check P8400
H/V_Sync/R/G/B Signal Line
R8408, R8409, R8410
ok
ok
ok
No
No
Re-download EDID data or Replace the defective IC
ok
Replace Jack
Check DSUB_DET
Replace R8425
No
ok
No
Check FRC and BCM LVDS Output
Replace Mstar(IC9001) or BCM( IC900)
or Main Board.
or Main Board.
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