Strange CF-28 Monitor Issue

Discussion in 'Panasonic' started by Toughbook, Dec 17, 2007.

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  1. Toughbook

    Toughbook Drop and Give Me 20!

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    Light grays and light blues is it. Any sold color and the screen is fine. This is really starting to tick me off. I've checked the connections... All of them. I'll do it one more time but I doubt it will help. I've never seen anything like it. Purples and yellows are okay. Medium grays are good too... As it gets lighter it starts to become apparent until it starts getting too light and then it fades out again! (White is not affected either.)

    I hate to scrap the screen as it is really bright and should last a long time. I would think.
     
  2. klboo

    klboo Notebook Evangelist

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    Does the error show up on an external display, or only on the LCD? Rule out video chip or memory issues?
     
  3. Toughbook

    Toughbook Drop and Give Me 20!

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    Great idea... Let me check!

    Edit... Hmmmm.... I just tried it on an old Dell 19" color monitor. I hooked it up and went into the BIOS. It was set to "Simultaneous"... I exited the BIOS... As soon as it got to the Win XP boot screen it just kicked over to the LCD... And it looks the same. I rebooted, went back into the BIOS and set it for "External" and it did the same thing! It kicked off the Dell CRT and reverted to the LCD... Even though the BIOS had it set to External!

    Do you think it would make a difference if I tried it on my LCD upstairs? Heck... I'll try it... What do I have to lose?
     
  4. Toughbook

    Toughbook Drop and Give Me 20!

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    It kicks off the LCD monitor too. Sounds like a video card problem, yes?

    I'll swap LCDs out with another laptop to see what happens. I can't believe that that even the external monitor wouldn't work.
     
  5. Modly

    Modly Warranty Voider

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    I'd say it sounds like a video card issue. Swapping the whole LCD over would clear up that question quick though...

    I wonder how difficult it'd be to solder in a new chip ;)
     
  6. stan.distortion

    stan.distortion Notebook Guru

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    I would have said cables to, seems to be the video chip though. I'm guessing you have already given the mobo a blast from a compressor? Are there any ghost images on the screen?
    cheers
     
  7. Toughbook

    Toughbook Drop and Give Me 20!

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    It is the screen... I just swapped it over to another CF-28 and the same thing comes up. No ghost images. The thing that slays me is that there aren't any bad pixels. I'm thinking a bad wire or connection somewhere. Either that or a bad resistor or transistor on the pc board that is embedded in the back of the LCD. Who knows... I'll save it to put on a junker laptop I'll sell at a reduced price. The touchscreen itself is in flawless condition. I'll swap in another LCD to go with the good looking touchscreen.
     
  8. cadillac

    cadillac Notebook Consultant

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    ToughBook

    I’m just pulling this out of my kester but why don’t you try to pull the back light out and check the light it’s self and the reflector to see if any strange is going on there.
     
  9. Toughbook

    Toughbook Drop and Give Me 20!

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    I have tried to replace backlights on two monitors. They are actually cheap considering that they can possibly give new life to an otherwise spent screen. Anyway... I tried on both and failed. I'm not sure why they don't work. I'll need to play around with it when I have more time. The backlights go for only $9.99 online. They are as thin as the thin type spaghetti. (Only 1mm wide!) and are VERY fragile. I have ordered some super thin heatshrink tubing which I need to use when sealing the ends... Instead of using black tape.
     
  10. Modly

    Modly Warranty Voider

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    Just for the fun of it, try swapping out both of the boards on the back of the LCD, as well as the cables.

    I'm not sure if the 12" parts would do you any good, but if you need a new board I've got the ones from my cracked 12".
     
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