Read LG 19LV2300 (CHASSIS:LA86D) Service Manual online
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TROUBLESHOOTING
Check P800 (Main PCB)
Pin # 9, 10, 11, 12
ST_5V Normal?
Replace the power board
NO
Check P800 (Main PCB)
Pin # 1, 2(16V), 5, 6(12V)
Are all the voltages normal?
Check a P800
wafer & a connector.
Are they OK?
NO
Replace the power board
YES
Check Q804 (Main PCB)
Pin # 5, 6, 7, 8
Are +5.0V OK?
Check Q804
Pin # 1, 3
Are ST_5V OK?
Replace Q804
The peak to peak
should be 3.3V on the pins.
Check IC407
Pin # 20, 21, 22
Are the logic signals OK?
Check IC805, IC809, IC810
Are all the outs amplitude
normal?
Find which IC doesn
’t have output.
Then, replace the IC you
’ve found.
Replace Q803
Replace IC407
*A
Quick trouble shooting tip for
system failure
1.
To boot up the system, it requires
1.2V, 2.6V and 3.3V poweronly.
2
.
So, check the outputs of the IC
805, IC809, IC810 first.
3.
If you can see the LD803 is on, it
means at least, 3.3V power
1.2V for IC805, 2.6V for
IC810, 3.3V for IC809
3.3V Should be on this pin
Check all the
power at IC407
NO
NO
NO
Check Q803
Base input(RL_On) of the transistor
Is the amplitude higher than 0.7V?
NO
NO
YES
YES
YES
(Follow next page
for MT8280FG)
YES
YES
YES
YES
BCM3553
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