troubleshooting - LCD screen inverter failure symptoms

25
2014-04
  • karatchov

    I have a toshiba laptop, it's about 4 years old, had been working flawlessly until ...

    Recently, the LCD screen started to show some artifacts, like flickering, screen freeze in dark image and corner starts to get brighter. Most of the flickering happens in a horizontal pattern (horizontal lines, parts)

    At first, moving the screen a little bit corrected the problem.

    Now, if it appears at startup, its very hard to get rid of it (the screen may get clean, but the problem reappear very fast).

    But sometimes, it just works fine.

    Searching in the web, I concluded this could be a screen inverter failure, but I have no idea if another piece of hardware could be responsible of this.

    Please note, the problem appears even before loading the os and an external screen works correctly.

    What do you think ?

  • Answers
  • MDMarra

    It could be the inverter, backlight, or the LCD panel itself.

    Backlight failure is usually hinted at by a pink hue to everything.

    Inverter failure usually results in the dimming of images on the screen to the point where the backlight is not even on (the inverter provides power to the backlight)

    This sounds more like it is a failure in the LCD panel itself, though it could just as easily be a loose data cable connected to the back of the LCD. If you're feeling adventurous and you laptop is out of warranty, you can take the LCD out of the bezel and reconnect everything, checking for loose cables along the way. It's really not that hard, and what do you have to lose? Either you pay to have it replaced, you fix it yourself, or you break it trying to fix it yourself, but you probably would have to get it replaced anyway.

  • nik

    It could be a backlight related problem or the connector just got a bit loose.
    I think, its time to get a service round with your laptop.

    My Dell had a loose display connector after about 5 years and one service round got it fixed.
    The service tech would also be able to tell you if you need any specific part replacements.

    If you really want to try this out yourself,
    I'd suggest at least getting the service manual for your model handy
    (calling the tech is the safest method though).

  • Col

    I'm not sure what causes the problem but it's quite common on laptops, I suspect it's something to do with the way the screen flexes when it's opened and closed since I've never seen it on a desktop flat screen. Whenever I've reported the fault to a laptop manufacturer they have always swapped the screen out (under warranty) so I expect that's what you'll have to do.


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  • John Rudy

    I was replacing my father's computer this past weekend, and he brought up a problem he'd been having with the "new" monitor my cousin recently gave him. ("New" is a very relative term; this monitor was new to my father, but definitely a couple years old. Unfortunately, I don't remember the manufacturer and model number.)

    The symptoms started perhaps 2 weeks ago -- that is, prior to me going out there and replacing the system. (So we can eliminate that change as a possibility here.) When he turns on the computer and the monitor, a massive white spot appears in the upper right corner of the screen, then steadily grows to fill the entire screen. About 2 - 3 minutes later, shutting the monitor off and then turning it back on will bring the screen (mostly) back to normal.

    (By "mostly," I mean that it will be usable, but you will see what appear to be horizontal refresh artifacts for another 30 - 40 seconds. After that, it'll be fine until the monitor is turned off again.)

    Is this an issue with the backlight starting up? Is the monitor on its last legs? Has anyone encountered anything like this?


  • Related Answers
  • William Hilsum

    Dead no, last legs, yes!

    It really depends on make/model, but this usually means a problem with the back-light / control circuit.

    If it is a "few" years old, it may be worth seeing if the manufacturer has a 3/5 year warranty you can claim on.

    I had this on a old Samsung monitor, I used it on a server where I only needed to turn it on once every week or so for 20 minutes, it lasted a further 2 years before it finally died (but this was low usage), if you are using it constantly, it would most likely be quicker so get a standby monitor ready!

  • Dave

    Inspect the power supply capacitors, and any other capacitors. There is an ongoing problem with poor quality capacitors in all kinds of electronic equipment manufactured between 1996 and 2007.

    Alternatively, replace the power supply board entirely.

  • Simon Sheehan

    Yes, It sounds like the capacitors in the power supply are about to go out. This is a very common problem. We repair monitors all the time with issues like you are having. Here is a link to a web page that shows what to look for on the power supply board and what needs to be changed to repair the board.

    If you can solder then you should be able to repair your power supply board yourself. If normally involves replacing from 4-10 blown capacitors and then the unit will be as good as new. It's worth checking it out before you trash the monitor.

    You could try looking at CCL-LA