Is this monitor about dead?

Discussion in 'Buying Tips, Advice and Discussion (archive)' started by DougJrS, Sep 24, 2005.

  1. DougJrS macrumors regular

    Mar 21, 2004
    Kansas City
    Good afternoon everyone.

    I am having some monitor problems and wanted to get everyones opinion as to what the problem might be. I have a dual 1.8 G5 with a ViewSonic PF790 monitor. The screen on the monitor (the image of the desktop) is moving depending on what application is up. If no application is un the left and right side of the screen is stretched off the side of the monitor about an inch and the screen is dark. If I open finder the screen comes back a little and most of the darkness goes away. If I open an application that takes more screen room (like Safari) the screen comes back to where it should and the color is ok. Now, in Safari in a scroll to the bottom of a page the monitor starts a high freq buzzing.

    And even more weird is that sometimes the screen image will only be like 2 inches wide and then will go to full screen when you open an application. Putting the machine to sleep and then waking it up seems to fix the problem for a few minutes.

    Anybody have a clue what is going on?

  2. lexfuzo macrumors 6502

    Mar 15, 2005
    The heart of Europe
    What happens when you try this:

    a) connect the monitor to another machine
    b) change resolution and refresh rate
    c) try different wallpapers (white, black) - is the effect the same?

    Could you take a picture of that and post it?
  3. DougJrS thread starter macrumors regular

    Mar 21, 2004
    Kansas City
    1) I will try this later today. I have a dell laptop (actuall work owns it) that I can attach.
    2) Same problem, on the screen moves around when you change the refresh reate and you have to use the little buttons to get it back in place. I have a friend that is a PC repair man that walked me through this on the phone to see if he could fix. (he loved it because he is always have PC problems, and I just tell him that everything works better on a mac, so it was a little payback I guess)
    3) WOW! I had the Clown Fish wallpaper and I went to 50% gray. This screen has a huge color problem. The gray color is not uniform across the screen. Also, white looks a little yellow and the windows have shadows. (is that an OSx thing that I just didn't notice before?) It didn't help the origional problem at all.

    When you say picture, do you mean with my digi camera? I tried a command shift 3, but the picture that it took looks fine.

    I got my dad to come look at it just a few minutes ago and he noticed that if you go from a white webpage to a black page (like from to the Nano page) that the monitor flashes, the windows "bounce" in size, and the color is off. He also noticed that if you take a window and drag it around the window that the screen moves (like goes off the edge of the monitor).

    Thanks for your help. As I get pictures and result with the laptop I will post. I really appericate your help!

    (BTW - does the 20in ACD have the same reported problems as the 23in HD ACD?)

  4. lexfuzo macrumors 6502

    Mar 15, 2005
    The heart of Europe
    No hurry. This is just to exclude that the the problem lies within the video card.

    That's perfectly OK that you have to adjust the screen a little after changing res or freq.

    Yes, mine have shadows too.

    Ah, yes, just to illustrate your description. A screenshot won't help since it actually doesn't shoot the screen but the graphics memory... So it should be named videocardshot instead, but I digress...

    It all sounds like an electric problem of your monitor to me.
    A CRT Monitor consists of two main electric parts:
    1) An unit (actually, 3, one for each colour) that accelerates electrons towards the screen. The acceleration is proportional to the brightness of the screen.
    2) An unit (actually, 2, vertical and horizontal) that deflect the electrons on their way to the screen so that they can fill it from top to bottom and from left to right.

    These units have to be synchronized and operate at high voltages. Additionally, the voltages change at a high frequency to steer the electron ray.

    This explains why the geometry of your screen image is influenced by the brightness: Ideally the electric systems of acceleration and deflection are independent. With older monitors it can happen (no idea why that is, though) that the system is not strong enough any more to supply stable power to all units.
    The acceleration unit demands more electricity to change the screen from black to white. When there is a weakness in the electric system this rising demand would disturb the deflection unit and therefore change the geometry of the screen.

    I don't know if that's the case with your monitor, but I witnessed it with others. btw: You don't have strong magnets around your screen by any chance? ;)

    You mean these color problems? - Sorry, no idea on that.

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