LCD Display Dim with New Inverter and New Screen


I would like to ask the community a question about screen dimness. I have an HP laptop that has a very dim display. I am an advanced computer user with years of experience fixing computers of all kinds. Hardware, software, you name it. What is strange to me, is that this screen is dim no matter what I seem to do. I have replaced the entire screen, changed out several inverters, changed out/removed sticks of RAM, reseated cables, replaced the cable from the motherboard to the back of the LCD display, and, of course, I have turned the brightness up all the way, and still nothing. The screen is still extremely dim. When hooked up to an external monitor, it works just fine so I am reasonably sure that it is not the video card. Any suggestions? Any input would be much appreciated.

Thank you!
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More about display inverter screen
  1. Does the screen stay the same brightness when the laptop is on wall power and battery? Try uninstalling and re-installing the power manager drivers.

    Issue could be with the screen even though you replaced it.
  2. I thought that as well. The battery and wall power have the same effect. And, oddly enough, since I've posted this, I've gotten another HP laptop into my shop with the same problem. I've tried the same things, switched screens, inverters, RAM, etc and still nothing.
  3. Hi :)

    I own a lappy repair company....and suspect i know the answer....

    The problem IS either the Inverter or Screen....


    You MUST change the Inverter for a BRAND NEW one with the EXACT same part number....

    If its still dim...

    Brand new Screen with the EXACT SAME part number (white sticker on back of screen)

    We see this all the time when customers THINK that ANY inverter or screen will work....they fit wrong ones and then come to us....we fit correct ones and all working...

    All the best Brett :)
  4. Quote:
    Hello, I have read all the responses on this post.. Have you fixed this issue? I work for a component level repair facility. What type of laptop is it, I didn't see that mentioned other than HP? One thing you need to be sure of is if you are swapping inverters you are using known exact working parts, all inverters are not the same. LCD same thing replace with identical part number(ie..LP***** or LTN****, or AU******, or B******) and I don't mean that of HP, where as inverter you want the same using the HP part#

    With that said have you tried an external monitor first? Once that is done if it looks the same on external you have a board issue with the video chip. If not try these not necessarily in this order, but insure your are checking with known working compatible parts from another machine:

    1.Chane CPU
    2. change memory only use one stick

    Now if none of these work you definitely have a board issue which is what we repair, we also have the ability to check the LCD and inverter outside of the machine. It is more than likely a resistor or capacitor on the board.

    Hope this helps.. :D



    Hi :)

    It is NOT the motherboard, and you are NOT allowed to try and sell your services here at Toms when answering questions....

    I do NOT advertise any of my computer companies here...including the Laptop repair company I own....

    Giving bad advice to get work from this site is NOT ON...


    All the best Brett :)
  5. I know it's not the motherboard. Remember, I am in the laptop repair business as well. These machines are not mine, they are customer's. I have repaired a thousand screens and LCD related problems and know a motherboard failure when I see one. Thanks for the input though. That being said, I have never seen a problem this persistent. I have changed out inverters and screens with the EXACT model number and still the problem continues. I am completely out of ideas and need something to tell my customers because honestly, I'm at a loss for the first time in many years. Thanks guys!
  6. Another option, is to get a whole screen assembly and wire it in. I have seen dim screens with good hardware but it was due to the power management software acting up, and it actually messed up the internal monitor calibration. This was in a desktop with a regular monitor though. Screen was viewable but was at 1/2 of brightness even at max. Had to reset the monitor to factory defaults and remove the power management software to fix.
  7. Okay update,

    I was switching out inverters again just trying to coax some sort of life from these machines' screens. Then something interesting happened. On one of the machines, no matter which inverter I tried (with the new screen, not the old) if I positioned the plug within the inverter JUST right, the bottom right hand corner would flicker to the brightness it should be. Does this make sense to anybody?
  8. I see you have gone through all the mechanics of resolving the Dim Screen, one thing I haven't seen is, is your BIOS up to date? I've had several laptops brighten up once the BIOS was updated. Some systems if you don't update the BIOS soon enough you can burn out the CCFL(s). I only had to replace the screen once due to that issue.
  9. Did you ever find a resolution? We are having the same issue with a Thinkpad T61

  10. jlemonds said:
    Did you ever find a resolution? We are having the same issue with a Thinkpad T61


    Lenovo/IBM think pad is a different monster. Make sure your BIOS is up to date first. Possible inverter failure. HP has had motherboard issues as well where you have to reflow the solder on the video processor. Usual signs are on and off video, Flickering video, or no video at all. You may want to see If there were any reports with your ThinkPad. NVidia Graphics are usually a problem. If that is your graphics processor, may want to really research if this is a common problem.
  11. jlemonds said:
    Did you ever find a resolution? We are having the same issue with a Thinkpad T61


    That's an old laptop, you will likely need to replace the backlight or inverter to brighten the screen.
  12. I know this is an old thread, but I had the same problem with a Toshiba laptop and found the solution. Even though I had replaced the screen and inverter, the screen was very dark and could be seen with a flashlight. Also, external monitor was perfect. The solution for me was the switch that puts the computer to sleep when the lid is closed. This switch was locked in the down position by a piece of debris. The screen will not shut off completely when this button is pressed, but it cuts power to the backlight only. Immediately after clearing the debris from the switch, it popped up and the screen came on. Subsequent pressing of the button revealed then that the backlight only is cut off.

    I hope this helps someone who has found this forum by searching for the problem the way I did. I also hope that this solves any of the already-posted problems.

    God Bless.
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