Monitor backlight or inverter or some other problem?

skervy

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Nov 27, 2007
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i have a megavision mv220 lcd that doesnt get much love on support :( ive been doing alot of reading and come down to it either being the backlight or inverter thingy. i dont know all of the exact causes and solutions to fix but im kinda figuring it out.

problem - i leave the computer on and turn off the monitor when i leave home. when i return and try to turn the monitor back on it shows a dim picture then goes black after 2 or 3 seconds. doesnt have any picture at all on the screen not even the no signal or menu will come up. restarting the computer will show the picture for 2 or 3 seconds at each screen (boot, windows load, windows startup). from what i can find on this issue its the backlight but im a little confused because from what i can find thats a permanent problem when the backlight goes bad. so far it only seems to happen when i leave the computer on for long periods with the monitor off. all of my power saving settings on the computer are off so i dont think thats a problem

solutions - if im turning the monitor on in the morning after it and the computer has been off for the night it seems to work fine. when the problem starts after the computer has been off with the monitor on turning both off for a period of time makes it work again.

so what id like to know is could it be something besides the backlight? money is kind of an issue right now so id rather not waste the money and trouble replacing the backlight or finding someplace to do it for me. this monitor has horrible support and information on replacement parts. i had to research for hours just to find out what kind of power supply i had to get when it broke
 

skervy

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no responses on this :( maybe this will help anyone that knows a little about lcds. i narrowed down exactly when the monitor screws up and how to get it working.

symptoms - anything over half hour or an hour of being off it wont turn back on. does the quick light up then goes black all lights go off

solution - put a small space heater near the back of it for a couple minutes and it turns on no problem

ok now all i need to know is what in the monitor would stop working when it cools down and require being warm to work
 

paulbtorrent

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if you put bright light at an angle close to lcd can you see a windows shadow
then .... (from a.n. other)

after two weeks searching I finally find doctor living stone
http://www.aplusperfect.com/articles/lcd_capacitor_repair

more fun with paulbtorrent

the takening the case bit off is like open your wallet a second time
after buying a new LCD, but you must! smallest two screw driver's flat headed, practice using two pennies stuck together()with your fingers after, one little () move and inch and {} again, with the case , it does not break, just need to lever open
[once open you realize they somehow put that old briefcase clip inside!]

also note the bright light test to do first to see if can see a windows screen , and that capacitors are one for a number of things that a make a inverter work! there a transistors as well, given that however, to replace all the capacitors on my inverter, was 11 capacitors, cost me $11 (uk ebay) and already had the iron and solder. So only cost me me $11 to try and see but no luck , still fun and I still can see the screen for 2 sec' at a time plus I have a spare set of caps now in the event that the new one do go burst! you have to laugh really, what next , a new on/off button
! come back all is not well mmmMMMMmmmMMMMmmmMMMMTimBernersleeMMMMMmmmmMMMMMmmmm
 

ampedal

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Skervy, this sounds more like an inverter issue to me.

If the screen lights up whatsoever - it's probably not the backlight. When the backlight is broken, it doesn't light.

The backlight is actually just a complex reflector for a CCL (cold cathode). Similar to fluorescent light bulb, the CCL stretches the length of your monitor screen, usually resides at the bottom of it, and is a few milimeters in diameter.

If the screen is still visible in a lit room (sometimes you have to look real close) - but is very very dim: it's probably the CCL

If it's having any other issues monitor-wise: it's probably the inverter.

I reccomend you search ebay for an inverter that matches your model monitor. If a new inverter doesn't fix the problem, you can sell it back (they retain value for a long period of time).

Good luck!
 

ampedal

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Another possible issue could be a buggy video card.

Try hooking a separate (and verified working) monitor to your system. If all is well with the 2nd monitor - it is definitely your mv220 LCD that's the culprit
 

skervy

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need to revive this since the monitor died some months ago. i thought it may be the power supply goin buggy so i replaced it but still no luck. the monitor will turn on then go blank after about a second. pretty positive its the inverter since the lights still come on. ive been hunting hour after hour for hints online for where to find an inverter or a similar one that would replace it with no luck. the closest ive found is that the inverter for the 17in model which you can buy replacements for has the same plugs. the only response to it was he could give it a try. does anyone at all have a solution for this like would it be possible to rig something up i would really hate to just trash this monitor its really nice and i only got to use it for about a year
 

skervy

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if it helps any it says mv179_inverter 2006.10.17 rev:1.2 im wondering if its possible the board was replaced before i got it. the main board with the power and video plugs says mv220 but the inverter is mv179
 

Sprint6

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The video board and the power board and the inverter are all made by different manufacturers and assembled in the unit.
Your problem sounds like the power board is dead / dying. but a word of caution is that if you keep forcing it to start by the tricks mentioned()which work you are compiling more problems and the fix will get more involved and cost more or even make the cost above that of purchasing a new one. reason being the shutting down of the video to the monitor is telling you that there is something failing, the tricks are adding a stress on the other components that are ether running now at a low-power, or out or range voltages causing other components to fail as a result. If you want to get it fixed email me at sprint6@zoominternet.net. And stop forcing it to come on, i have gotten these unites that have been used this way and have become unrepeatable, when a simple component had started to fail originally.

i have set up a UPS shipping agreement to make it possible for a customer to send the unit in for repairs/ estimations, to make it easier for them to ship the units at no cost, until the unit is actually repaired. With all cost involved discussed and agreed upon before billing,
 

ampedal

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Don't listen to the guy above, fixing you computer is not a "trick" - and does not create more problems. In fact, fixing your computer will typically just fix your computer....

You may want to contact one of the many companies (searcable on google) who sell inverter boards. Tell them your model number, and pay attention to return policies.

I have done this many times, with great success...best of luck!
 

Sprint6

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Sorry for any confusion, my post should have said "WITHIN" the monitor not "TO “the monitor. Problems within the monitor have nothing to do with the computer being at fault most of the time.

The tricks were the ones that temporarily bring the monitor back to life. I did like the addition of the one warming up the monitor first; I have got to try that one. All depends on which components are failing.

Be glad to hear any other discrepancies.
 
G

Guest

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By far the most common issue with flat screen monitors I've encountered is a simple capacitor failure on the main power supply board. This seems to be caused either by faulty components or ones not rated for the actual temperature inside the casing.

Diagnosis is simple if the capacitor has bulged (though it won't always bulge but still may have failed). Replacement costs very little and can be done by anyone with soldering skills.
 

skervy

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I was going to try selling it as a parts monitor to see if i could recoup a little money from it since the screen and everything else is great. But i never thought to check the power board. The inverter doesnt have anything that appears burned out ill try looking at the other board and see if i find anything

Quick edit i have the backplate off now so i could get to the power board and noticed the screen is a samsung LTM220M1-L01. Also i dont see anything wrong with the board caps all look fine and no burns
 
G

Guest

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As I said, failed capacitors don't always bulge or leak. I would routinely replace the ones in the 16volt (or so) range as in my experience these are the ones affected. Removal is simple if you have a solder iron and hand solder pump -- purchase is cheap and straightforward at a hobby store if you take a sample with you. Replacement even simpler (just observe polarity)
 

Sprint6

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If you have a digital camera please take some photos of the components inside the monitor, a good sharp image of the id of the boards will also be helpful, then email me at Sprint6@zoominternet.net. And then i can see what you are doing and may be able to help.
There is also several other components that fail besides the caps, but you said you had replaced the power board in the monitor, so you may want to look at the video board as well.
Good Luck
 

skervy

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No i didnt replace the power/video board just the external power supply. I was wondering if itd be possible to just get other replacement parts for this specific screen since its samsung and not a random no name. Tried looking for a while last night and couldnt find anything but the screens. Ill get a couple pictures and send em to you though i dont have the greatest camera so wont be able to get clear close ups of things