Laptop screen blacks out randomly

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  1. Posts : 128
    MS Windows 7 Ultimate 64-bit SP1
       #1

    Laptop screen blacks out randomly


    A couple weeks ago my laptop screen started turning off randomly. It took me a while to figure out that the computer was still running, the screen just shut off. Closing and reopening the lid turns it back on, sometimes for the rest of the time my computer is on, sometimes just for a few seconds. There is apparently no way at all to trigger it, it just happens.

    I hooked it up to an external monitor (and set it to duplicate the screen), and the external monitor doesn't shut off when the laptop screen does, so I know it's not a video card issue. I've also run full scans with Malwarebytes and MSE, so I'm sure it's not a virus/malware problem. Also, I was able to make the screen turn back on by changing how to use the dual monitor setup with the other monitor connected. (Changing from "duplicate desktop" to "extend desktop" and vice versa) Which means either my LCD screen or backlight or something is messed up, or else my computer randomly thinks the screen is closing for some reason (since it's just set to turn off the screen when the lid closes, not shut down or anything). And if it thought the screen was being closed, I'm pretty sure it would come back on as soon as I moved the screen a bit, and wouldn't have to completely close and reopen it to correct the issue. For these reasons, I'm fairly certain it's an LCD-related hardware issue, but I really don't know how to be sure.

    So I have two questions:
    1) can anyone help me confirm/correct my theory about what's going wrong (and tell me how to fix it?), and
    2) as a short-term workaround, is there any way I can create a shortcut on my desktop that can be clicked to refresh the screen? Not like an f5 refresh, I mean to totally refresh the whole screen like what happens when changing screen resolutions. Because that seems to bring it back, and would be easier/faster than having to keep closing and opening the lid.

    Also: I never get any errors related to this, and device manager doesn't show any problems with anything. I suppose Event Manager could have info about it, but I have no idea where to look in there.

    Thanks!
      My Computer


  2. Posts : 45
    Windows 7 Ultimate 32bit/x86
       #2

    It can be faulty backlight or the inverter. I had the same problem with my laptop screen, it was on for like 3 or 4 minutes the it would turnoff but windows was still running. I hope you can resolve it soon:).
      My Computer


  3. Posts : 12,364
    8 Pro x64
       #3

    Slammer said:
    There is apparently no way at all to trigger it, it just happens.

    I hooked it up to an external monitor (and set it to duplicate the screen), and the external monitor doesn't shut off when the laptop screen does, so I know it's not a video card issue.
    Did you disable the laptop screen with the external monitor connected to see if the blank screen is replicated?

    (I suspect the external wont go blank however)

    And do you always have an external monitor attached, or is that just being used for testing atm? ie You normally use the laptop screen only.


    Also, I was able to make the screen turn back on by changing how to use the dual monitor setup with the other monitor connected. (Changing from "duplicate desktop" to "extend desktop" and vice versa)
    Doing that is similar to triggering the closing/opening or on/off of the LCD.

    For these reasons, I'm fairly certain it's an LCD-related hardware issue, but I really don't know how to be sure.
    From what you've described already, it does indeed sound like a hardware issue relating to the screen. it could be something like a loose wire/cable or a faulty sensor (ie the one that detects the opening/closing of the lid).

    The intermittent nature of the fault tends to back this up.

    One temporary test/workaround could be to assign the 'do nothing' action to the Lid closing option in the power config to see if that makes a difference.



    I've also run full scans with Malwarebytes and MSE, so I'm sure it's not a virus/malware problem.
    Ditto. Doesn't sound like virus behaviour.
      My Computer


  4. Posts : 128
    MS Windows 7 Ultimate 64-bit SP1
    Thread Starter
       #4

    Thanks for all the input! I didn't actually disable the laptop screen while trying that, but I'm confident the external monitor would not go blank, like you theorized. I do not usually have an external monitor attached, just used that for testing purposes. Although right now I usually just open and close the lid 5-10 times when I start the computer and it's usually good for the rest of the day after that, or for at least a few hours.

    The only way I can describe it is that it seems to get "strained" shortly after I open and close the lid (screen brightness flickers slightly for about a second) and if it can get past that a couple times, it'll work without a problem for hours on end. Like I said, jiggling the screen back and forth neither helps nor makes it worse, which makes me think it probably isn't a connection issue (based on my limited knowledge of how these things work)

    I actually do have the lid-closing assigned to "do nothing," which just causes the screen to turn off when closed (probably to save power; I don't think I can change that behavior for that option)

    If it gets to the point where it won't stay on for more than a couple of minutes at a time regardless of what I do, I may just hook up an external monitor until I get it fixed, although that will be a bit of a pain. Are you aware of any command-prompt way to simulate the closing+opening of the lid, or to refresh the screen resolution, or something that would cause it to refresh? Then I could just create a shortcut for it and assign it a keystroke for when this happens. If it's a connection issue, at least that should (in theory) keep it from getting worse, and be much easier and faster.

    Thanks again for your extensive response, I appreciate it.
      My Computer


  5. Posts : 128
    MS Windows 7 Ultimate 64-bit SP1
    Thread Starter
       #5

    Ok after a little more testing I've been able to determine that it's just my backlight that is shutting off on me. When I shine a bright light on the screen I can still see the pixels and whatnot, there's just no light coming out of from it. So now my question is: what needs to be replaced? Looking around online, I think I just need to replace the inverter board (which would be great because I can get one for under 10 bucks on eBay). But I don't know enough about screen technology to know if the whole LCD screen needs to be replaced (probably more like $60). Can anyone confirm whether or not replacing the inverter board would solve the problem of the backlight turning off? Or is there any way to be sure? Thanks!
      My Computer


  6. Posts : 128
    MS Windows 7 Ultimate 64-bit SP1
    Thread Starter
       #6

    Another question: I've determined that my Inspiron 1545 uses a CCFL-backlit LCD screen instead of an LED-backlit one (and therefore uses an inverter board I think needs replacing from my previous comment). If a new inverter board doesn't fix my problem, it it possible to just buy an LCD-backlit screen and plug it directly into my computer somewhere, bypassing the need for an inverter board at all? The LED ones are like $50-60 cheaper, and that would be a great backup plan if the inverter board turns out to not be the problem, and the whole screen needs replacing.
    Last edited by Slammer; 21 Apr 2012 at 13:18.
      My Computer


  7. Posts : 12,364
    8 Pro x64
       #7

    Unfortunately Laptop hardware isn't my forte so I'm reluctant to say "yeah, grab this and that, it'll work" only to have you discover that it doesn't work and you've wasted your money on bad advice.


    I'll see if I can find someone with more expertise in laptop hardware.
      My Computer


  8. Posts : 483
    Windows 8 64 bit PRO
       #8

    I replaced a few laptops screen. The inverter going bad seems to be the problem(from what you descrive) and the only way to fix it is to replace it.
    There is no need to replaced your LCD screen, unless it has dead pixel or is crack. However nothing is ever 100% certain.
    Make sure to buy from a place with a good return policy.

    I dont quite understand your last question...
    Extra:
    Correct backlight type for your new screen | LAPTOP SCREEN, LCD panels from $42.
    This has information and pictures you will find useful.
      My Computer


  9. Posts : 128
    MS Windows 7 Ultimate 64-bit SP1
    Thread Starter
       #9

    Thanks chris. That's exactly what I was hoping to hear. I've ordered a new inverter board on eBay for about 7 bucks, so even if someone on eBay finally decides to rip me off and sends me a crapped out one, I can easily afford to just buy a different one.

    My worry was basically that it might be a problem with the actual cathode ray tube inside the screen, and thought I would have to replace the whole screen if that was the part that was bad. But after a little more research (and some thinking) I figured that if the bulb was the problem part, it wouldn't be coming on at all (assuming it works in roughly the same way as normal bulbs). Hopefully this new inverter board will fix all my problems!

    As for my unclear question: I read that LED-backlit and CCFL-backlit screens are NOT interchangeable. But the LED-backlit kind are much cheaper, and mine uses CCFL ones. I was basically just asking if it anyone knew of a way to hook up an LED-backlit screen into a laptop that had been using a CCFL screen. Which I've come to realize is a bit of a ridiculous question since that would probably vary from model to model. But I don't think it'll matter anymore since the new inverter board should fix my problem.

    And if for some reason the CCFL bulb IS the problem, and the inverter board is working fine, I found a site that gave instructions on how to replace the bulb instead of buying a new screen. Meaning a new screen shouldn't be any concern any more.

    And thanks for that website, that's actually where I went to figure most of this out :)

    Thanks again for everyone's input, the new inverter should be here by the end of the week, and I'll post an update when I have it installed.
      My Computer


  10. Posts : 128
    MS Windows 7 Ultimate 64-bit SP1
    Thread Starter
       #10

    Ok just got the new inverter board in today, and it didn't help. Still getting blackout issues. Although I did discover that the plug in my motherboard I thought could be used for an LED screen is actually for a built-in webcam, so I definitely have to stick with older, more expensive CCFL equipment.

    I guess my next best move is to buy a replacement CCFL lamp and replace the one in my screen? Or are there other, less invasive things I can try?
      My Computer


 
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