help me repair 22 lcd monitor. Have replaced caps and measured the output Voltages

UnnamedUser159

Joined May 3, 2016
501
We have Lg monitor 22 that show picture for a second /picture 1/ then goes black and then again broken picture/picture1/

What i have done : replace all the caps on the power supply except the big one.

I measure the volgates the blue cable to first three gray and to second three gray and it shows 5.05 5.05 000 3.3 2.45 2.95

I measure the voltages without CCFL connected, only the display board

thanks

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Joined Mar 10, 2018
4,057
Can you remove panel bezel so that you can look at row/column
drivers on its periphery ? Under a microscope or magnifying glass ?

Look for solder cracks around thru hole areas and smt soldering.

Sounds like a possible thermal problem caused by mechanical/solder problems.
Or connector problem.

Regards, Dana.

wayneh

Joined Sep 9, 2010
17,153
Those lines look like a bad/damaged connection to the panel. I don't think they have anything to do with the power supply.

killivolt

Joined Jan 10, 2010
805
Those lines look like a bad/damaged connection to the panel. I don't think they have anything to do with the power supply.
Or maybe a bad video processor board.

kv

SLK001

Joined Nov 29, 2011
1,548
The "one second to black" failure mode usually indicates a backlight problem. If it is an LED model, then you have a burnt out LED diode or two. If you have a CCFL backlight model, you have a bad tube. What you did was not necessary.

UnnamedUser159

Joined May 3, 2016
501
i connect 2 visually healthy CCFL and they do as follows light go dark light go dark and that`s that.
I am begining to think and check. Advices are good accepted if i fail.

W2241S

Have 1.82v/eh13a/ 3.35v/eh16a/ on the regulators on ad board.

14.46 on vcc of LAF001

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