Getting a working LCD

Discussion in 'General Electronics Chat' started by magnet18, Apr 18, 2011.

  1. magnet18

    Thread Starter Senior Member

    Dec 22, 2010
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    Hi everyone, I'm working on a project that I need a working LCD display monitor for, and I have 3 options (that I'm willing to try)

    1. I have an emachines model 780 LCD monitor, and I managed to figure out how to power it, (it takes a 12V supply from a pigtail on the display cord... confused me)
    but it doesn't seem to want to turn on, after playing with it for a bit, I got it to come on once, but after a few seconds it faded to white and shut off :(
    not sure how easy that will be to fix, but it is my preferred course.

    2. I have 2 inview LCD's designed to be placed on projectors (what I actually want to do)
    one of them has the appropriate connectors, but will only support a display of 640 by 480 or lower (gotta love 90's tech), and my computer (vista, 32bit) will only support a display of 800 by 600 or HIGHER, so does anyone know a way to reduce that, or if XP will support a display of that resolution? because I think I can mash a couple old XP units together.

    3. The other inview LCD should display should handle the resolution, but all of the connectors on it are female... would simply getting (or splicing 2 male cables together) be a viable option, or is a female input different in setup, or is splicing 2 male cables together more complicated than just cutting, stripping, soldering, and taping?

    or if anyone has any other ideas on how to get a working LCD of a decent res. or a projector (what I'm ultimately making with the LCD) for free/ <$20 in a short amount of time, they would be greatly appreciated.

    Thanks :)
     
  2. Jotto

    Member

    Apr 1, 2011
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    17
    LCD's can be on, but not show a picture. Fading to white could mean a couple of things.

    1. Your TFT screen is bad, your A/D board is having problems. On the TFT being bad, its just going to have to be replaced, A/D board check your voltage regulators first. There will be 12vdc, 5vdc, 3.3vdc and 1.75vdc, not all voltage regulators have a TO220 case.

    On making LCDs into a projection type unit, going to need three screens to accomplish this. Each screen will control one color, an of course your going to need a lamp from a projection type unit. The last screen will require the contrast/brightness turned up the highest with each of the other screens being less then the previous one.

    I would take each screen down to just the TFT screen and apply signal to the unit to see if there is a picture, don't need the inverters any way. This is a fun project, but the quality is a bit lacking. Have fun with convergence its going to be tricky, but if you have a pattern generator use the dots on one screen at a time, then add one at a time to see if its matching up correctly.
     
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  3. magnet18

    Thread Starter Senior Member

    Dec 22, 2010
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    Alright, thanks, I'll check the voltage regulators and the TFT screen.
    Why does it need 3 screens for a projector instead of one though?

    Anyone have any thoughts on the other ideas?
     
  4. hgmjr

    Moderator

    Jan 28, 2005
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    The three LCD screens are probably being used to handle color. One is for red, one for green and one for blue.

    hgmjr
     
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  5. magnet18

    Thread Starter Senior Member

    Dec 22, 2010
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    What's wrong with using a standard RGB screen though, why is it necessary to use one for each?
     
  6. hgmjr

    Moderator

    Jan 28, 2005
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    I am no expert on projection TV but for whatever reason many of these used the three screens through which the different colored lights (red, green and blue) were shined with each the three screens set to pass only its color from the scene onto the projection screen. I suspect that is the only way they could get the brightness needed to achieve the overall brightness on the projection screen.

    hgmjr
     
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  7. magnet18

    Thread Starter Senior Member

    Dec 22, 2010
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    OK, that makes sense, thank you :)
     
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