Dr!113rK!113r

UnDead LCDs

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I keep seeing all these " non-functional or defective" LCD monitors on ebay and I was wondering what could be wrong with these things? Is it worth it to spend say 30-40 bux on one and try to repair it? I have a pretty basic understanding of how to repair electronics, but would these thing more often than not require a very advanced understanding? Any thoughts?

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I keep seeing all these " non-functional or defective" LCD monitors on ebay and I was wondering what could be wrong with these things? Is it worth it to spend say 30-40 bux on one and try to repair it? I have a pretty basic understanding of how to repair electronics, but would these thing more often than not require a very advanced understanding? Any thoughts?

I'm not sure if it'd be worth your while, as some of the components may have gone bad and it wouldn't be an issue of a simple fix. Perhaps a critical component went bad, and you'd end up spending more for a replacement component than you would for a new, working unit (since you couldn't get bulk discounts like a manufacturer would). Keep in mind, I'm no electronics or manufacturing guru, so my opinion may very well be worth shit. :P

However, if you do decide to do something like this, take pictures and write an article - that'd be cool stuff to know.

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It's usually a backlight malfunction. Not always though, try to get as many of the symptoms as possible before buying. Anything other than that is almost certainly not worth repairing. Even repairing a backlight saves only around 50 bucks in most cases.

One of those "broken" lcds with no backlight makes a great homebrew projector though. You can either go the overhead projector cheap route, or an enclosed box with a nice fractal lens, but that costs a little more and is more involved. However, it wouldn't look like the the Bride of Projectorstein in the living room.

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It's usually a backlight malfunction. Not always though, try to get as many of the symptoms as possible before buying.

What would be some of the symptoms of a backlight malfunction?

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A very very faint image. Shining a flashlight on it reveals the image a little better.

It's sometimes is the inverter if it isn't the backlight, and can be hard to tell sometimes for someone who hasn't seen it a few times before. If your comfortable checking things out, you can try checking the contacts around the inverter board. It usually has a high voltage sticker on it. After you find it you can check the contacts with a soldering iron. If they are all good, and it isn't the backlight, it's probably a bad inverter board, and since you know where that is now, you can find out how much they are and add that to the cost of the monitor.

So, Monitor + Backlight or inverter (sometimes both the first couple times and you misdiagnose) and you have the cost. You just have to search around and see how much those parts are for any monitor you buy.

HTH

Edited by Evolve
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with all the laptops ive had, the backlight was on the motherboard. so if that was the cause, the LCD is fine, just some person didnt want to pay the 50 bucks for a new backlight (it was in one of my cases) it may be more expensive now though.

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It's usually a backlight malfunction. Not always though, try to get as many of the symptoms as possible before buying. Anything other than that is almost certainly not worth repairing. Even repairing a backlight saves only around 50 bucks in most cases.

One of those "broken" lcds with no backlight makes a great homebrew projector though.  You can either go the overhead projector cheap route, or an enclosed box with a nice fractal lens, but that costs a little more and is more involved. However, it wouldn't look like the the Bride of Projectorstein in the living room.

whats this fractal lens stuff? ive seen the one with the overhead projector...its pretty badass regardless. do you have a link to the one using a fractal lens?
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Most of the issues with LCD's on ebay are to do with the backlights, i've bought about 8 now for a flight simulation project me and my buddys are working on, we simply pop them out of the casings, replace the defective part and bung it into the plane :D

As for making projectors, yeah they are excellent for it, but only if its a very very small screen, under 640x480 pixels, with mines I used one from an in-car DVD player. any bigger and your going to have problems building it. If anyone is interested in building one all you need to do is make a board with about 12 extra bright led's, perfect for this job because they dont generate much heat, meaning your lcd screen isn't going to melt when you watch 100inches of high quality movies. Place that behind your busted LCD, and mount it in a box. Wooden box, not cardboard. Then all you do is get a PROPER lens, nice glass one not a plastic frenzel lense of ebay, then build it all into the box, with some heat holes in it, paint it the same color as your wall and mount it. With mine i have it connected to an extension wire which runs into the comps tv-out, or the satellite box, depending on what im watching. Had it running since 2003, who needs the odeon?

:D

Edited by skoby
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Don't you mean "fresnel lens"?

Indeed, that is what I meant :blush:

Nenn, check out the projectors those guys have built over at http://www.diyaudio.com/forums/ , under the post your results sticky. They run the gamut from this:

projector1mr.jpg

To this ghetto mockup:

mockup4mm.jpg

For anyone interested in building a good projector that your wife would actually let into the living room, this is the place to get help with it.

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