LG 42LG70YD (CHASSIS:LJ83A) Service Manual ▷ View online
- 25 -
Check signal format
Is it supported?
Check signal, Hsync, Vsync
C745, C746, C747, R839, R843
Replace it.
Check signal
R729, R730, R731
Y
Y
N
Check P701
Replace connector
Y
N
Y
Replace it
N
Maybe BCM3553(2)(IC100) has
problems
Check L703 Voltage Level 9V
Y
Replace L703 / Q701 / Q703 / Q704
N
Check Signal
C635, C636, C637
Y
Replace it
N
Check RGB Cable
Y
6. RGB Video
- 26 -
Check signal format
Is it supported?
Check signal
R755 (Composite), R740 / R741 (S-Video) (Rear)
R797 (Composite)
Replace it.
Check signal
C651 (Composite), C648 / C649 (S-Video) (Rear)
C652 (Composite)
Y
N
Check JK701 (Rear)
Check P700 & Cable (Side)
Replace connector
Y
N
Y
Replace it
N
Maybe BCM3553(2)(IC100) has problems
Y
Check AV Cable / S-Video Cable
Y
7. AV Video
- 27 -
Check signal format
Is it supported?
Y
Check JK600 / JK601 / JK705
Replace connector
Y
N
Y
Check HDMI Cable
Check EDID NVRAM (IC603, IC604,
IC700)
Power & I2C Signal (#5, #6)
Replace it or redownload
Y
N
Check HDCP Key NVRAM (IC102)
Power & I2C Signal (#5, #6)
Replace it
Y
N
Check IC806 #2 Pin Voltage Level
3.3V
Replace it
Y
N
Check C609 Voltage Level 3.3V
Replace it
Y
N
Check IC601 Clock Signal
#26, #27
Replace it
Y
N
Maybe BCM3553(2)(IC100) has problems
8. HDMI Video
- 28 -
Make sure you can’t hear any audio
Check Signal
L504, L506
Replace it.
Check Signal
L507, L508, L509, L510
Y
N
Check IC501 Power 19V, 3.3V, 1.8V
L500, L501, L502, L503
Replace L
Y
N
Y
Replace it
N
Check Connector
P500
Y
Check BCM3553(2) I2S Output
R627, R628, R629
Y
Replace it.
N
Replace connector
N
Check speaker
Y
Replace speaker
N
Maybe NTP3000A has problems. Replace it
Y
9. All Source Audio
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