Fixing a LCD Monitor?

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GoStumpy

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Sep 14, 2011
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Anyone ever undertaken this? I'm thinking there may be something wrong with caps, bulb, something of the sort...

Thinking I'd like to give it a shot, no harm in trying, right?

Monitor in question:

46699.jpg


Acer AL2416WB 1920x1200 resolution
 

GoStumpy

Golden Member
Sep 14, 2011
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I took the panels off the monitor today, and almost everything looked fine... no swollen caps, but there was one slightly discolored cap... a bit of a brownish color on one side, could that mean overheated?

The symptoms are, press the power button, the screen flashes once (nothing coherent, just a bright flash) and then its black. The power LED stays green.

Any ideas?

Found this link, wondering if I should test out my soldering skillz.... Anyone solder a PCB with an ordinary soldering gun?

http://www.aplusperfect.com/articles/lcd_capacitor_repair
 
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Selenium_Glow

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Jan 25, 2012
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It's worth a shot. But make sure you don't keep the rod in contact with board for too long. The excess heat then transmits to the adjoining areas causing them to blow out... or what ever that phenomenon is called. I've been in some monitor repair shops and what you'll be attempting is pretty much how they repair and service the monitors.

I tried fixing a really old mp3 player once, and the adjoining resistors blew out because my soldering rod was in contact with the board for too long.
 

pcgeek11

Lifer
Jun 12, 2005
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I took the panels off the monitor today, and almost everything looked fine... no swollen caps, but there was one slightly discolored cap... a bit of a brownish color on one side, could that mean overheated?

The symptoms are, press the power button, the screen flashes once (nothing coherent, just a bright flash) and then its black. The power LED stays green.

Any ideas?

Found this link, wondering if I should test out my soldering skillz.... Anyone solder a PCB with an ordinary soldering gun?

http://www.aplusperfect.com/articles/lcd_capacitor_repair

They had some with bad defective transformers: See this thread:

http://www.techsupportforum.com/for...or-goes-dark-black-after-a-second-379863.html
 
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mindless1

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Aug 11, 2001
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Hook a video signal up to it then shine a flashlight at it sideways to see if you can make out anything on the screen, it could be the monitor is working but not the backlighting (tubes or inverter circuit).

Don't know what to make of the brownish capacitor, we'd need a good picture. Could just be they used some cement/glue/etc on the board and heat turned it brown over time. "Usually" if a cap problem is bad enough to make the monitor display nothing from unstable logic circuits, the PSU protection circuit shut it down and the monitor LED flashes or changes from "on" to standby color, if not shutting off completely.

With a multimeter you could measure output voltages from the power supply board. Be careful, considering the inverter circuit on CFL lit monitors produces a few thousand volts. If shining a flashlight doesn't let you see any image, try unplugging the CFL tubes and try again, maybe the inverter has a short and without a load it stays working, but otherwise the main logic board may be damaged.
 

GoStumpy

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Turns out he wants to get it checked out by his other electronics friend, who apparently works with PCB's... I told him to keep me updated if they figure it out, and if he can't get it working he'll let me toy with it some more...

Until then I'm just waiting :)
 

chisaipete

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Jan 20, 2005
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www.chisaipete.net
I took the panels off the monitor today, and almost everything looked fine... no swollen caps, but there was one slightly discolored cap... a bit of a brownish color on one side, could that mean overheated?

The symptoms are, press the power button, the screen flashes once (nothing coherent, just a bright flash) and then its black. The power LED stays green.

Any ideas?

Found this link, wondering if I should test out my soldering skillz.... Anyone solder a PCB with an ordinary soldering gun?

http://www.aplusperfect.com/articles/lcd_capacitor_repair

Is the brownish cap bulging? Sounds like a busted cap to me. Also, the symptoms point to a busted cap--is the back-light simply off?
 

Matt1970

Lifer
Mar 19, 2007
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I do those repairs all the time. Typicly if you get the initial flash on the screen then the caps in the power supply are fine. Turn the monitor on while hooked up to your computer and shine a flashlight on the screen and see if there is a faint image.
 
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