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justin_otherguy
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Last Activity: 09-21-2010, 11:44 AM
Joined: 09-02-2010
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  • justin_otherguy
    replied to Viewsonic VA1912wb problems
    in Troubleshooting Computer Displays
    Re: Viewsonic VA1912wb problems

    I have tried to get the white balance menu to come up repeatedly, to no avail.
    I did narrow down how I got the one show in the attached pic.

    I can only seem to get the main menu [1], acontrast/brightness [^] or [v], reset brightness [^]+[v], and the one in the pic... [1] + [^] or [1] + [v], [2] will toggle between DVI and Dsub inputs. And the speakers will mute.

    It's just become Bizarro Monitor!
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  • justin_otherguy
    replied to Viewsonic VA1912wb problems
    in Troubleshooting Computer Displays
    Re: Viewsonic VA1912wb problems



    The voltages are on my latest pics... #28
    I wasn't real sure of the pin numbers, so I just made it visual....
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  • justin_otherguy
    replied to Viewsonic VA1912wb problems
    in Troubleshooting Computer Displays
    Re: Viewsonic VA1912wb problems



    I was able to see a box pop up, but I think because of my strange screen colors, cannot read it. Pic attached. The little slider does move from left to right, but I don't seem to have any control over it, and it doesn't change anything that I can see.



    Okay, more pictures attached.

    U4 & U6 = AMC1117 -3.3 F0550J
    Q8 = ZCPn...
    See more | Go to post

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  • justin_otherguy
    replied to Viewsonic VA1912wb problems
    in Troubleshooting Computer Displays
    Re: Viewsonic VA1912wb problems




    I'm not sure what is supposed to happen with the white balance. I press the keys, no menu, no change in screen.

    Factory defaults - I assume you are talking about the one in the regular menu, that has no effect also. The manual really lacks some details.

    Firmware update: I was able to find the MStar app. I haven't actually tried to find the correct firmware yet because I don't know if there is anyway to even do the update without that hardware that looks like it plugs into a parallel port and the...
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  • justin_otherguy
    replied to Viewsonic VA1912wb problems
    in Troubleshooting Computer Displays
    Re: Viewsonic VA1912wb problems



    I was able to reseat the 3 ribbon cables to the logic board. This produced no change in the symptom.

    I keep going back to the fact that this was not my original problem. It was a screen flicker only. The only thing I changed originally was 2 caps. The flicker was fixed but then the "negative" image reared its ugly head. Since then, nothing I've done has had any change.

    To my thinking, 2 things are possible.
    1) I somehow screwed something up on the power board with my iron. And I have...
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  • justin_otherguy
    replied to Viewsonic VA1912wb problems
    in Troubleshooting Computer Displays
    Re: Viewsonic VA1912wb problems

    Maybe this pic will help more. Don't know what I was thinking, but there are two sides to the header and I only measured one. In addition, I didn't realize there were labels printed on the board, so I included the pin labels on the pic too.

    I do have a service manual with schematics but I have to admit that most of it is greek to me. I have a little electronic experience, but am very rusty.

    Does anyone know if this is even a common problem? I've searched and found a few instances of it, but no solutions yet....
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  • justin_otherguy
    replied to Viewsonic VA1912wb problems
    in Troubleshooting Computer Displays
    Re: Viewsonic VA1912wb problems



    Ah okay. Well, the results are interesting I think. Strange voltages on some of the pins, I think. (see attached pic) I measured twice to be sure.
    There was no input signal attached, only power.

    Voltages green are at power on when green LED is lit.
    Voltages amber are after about 5 sec when the LED switches to amber....
    See more | Go to post

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  • justin_otherguy
    replied to Viewsonic VA1912wb problems
    in Troubleshooting Computer Displays
    Re: Viewsonic VA1912wb problems



    I found a service manual, but it hasn't been very useful. I found how to get into the "white balance" menu that I read about in another post somewhere, but I couldn't get that to work. Other than that, it mostly seems to troubleshoot to board level, not component.



    To be honest, I don't know what I would be looking for. I have multimeter, are there places I should be looking for "standard" voltages?



    Yes, time and again. The board is actually very well...
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  • justin_otherguy
    replied to Viewsonic VA1912wb problems
    in Troubleshooting Computer Displays
    Re: Viewsonic VA1912wb problems

    I went ahead and did the two 10V caps and that made no difference. Was kind of expecting that but hoping it would all come back to life.

    ETA: Now I dont know if this is a stupid question or not, but when I put the boards back together and plug the monitor into a PC, there's no metal cover or case on the monitor... would that in any way make a difference? I do have the ground screw in the board and one other. Just trying to think if its a dumb mistake I'm making. The color was fine when I started. Just flickering. I looked to see if I...
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    Last edited by justin_otherguy; 09-03-2010, 04:20 PM. Reason: edit to add more text

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  • justin_otherguy
    replied to Viewsonic VA1912wb problems
    in Troubleshooting Computer Displays
    Re: Viewsonic VA1912wb problems



    Perhaps I will go ahead and replace those as well then... not much to lose at this point.
    I have not removed the logic board at all. The ribbon cables appear to be well attached. Not sure how to remove them... do they just pull out?...
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  • justin_otherguy
    replied to Viewsonic VA1912wb problems
    in Troubleshooting Computer Displays
    Re: Viewsonic VA1912wb problems




    I just realized I made a mistake... the two smaller "new" caps are 220 uF. I mis-labeled them in the pics as 1000uF... guess it doesn't really matter, just makes for a great "well i'm an idiot" moment. ...
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  • justin_otherguy
    replied to Viewsonic VA1912wb problems
    in Troubleshooting Computer Displays
    Re: Viewsonic VA1912wb problems



    I tried that, but to no avail. Found a service manual online and tried to access the white balance menu. I couldn't get it to come up, but now I have something else to read. Will keep looking....
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  • justin_otherguy
    started a topic Viewsonic VA1912wb problems
    in Troubleshooting Computer Displays

    Viewsonic VA1912wb problems

    Hello, I am happy I found this place.
    I have a Viewsonic VA1912wb that started out with one problem and ended up with another.

    It began with a flicker that would go away after the display warmed up. It got gradually worse so that it would flicker constantly, but the colors were good this whole time.

    So I surfed around on the net and found that people were replacing bad caps on the power board for this problem. I popped the case open and found 2 caps that were bulging on top. These were twin 220uF 25V caps. I replaced them with ones from Radio Shack. They were...
    See more | Go to post
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