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Sunday, February 05, 2006

Replacing a Laptop's LCD Backlight

     

The first step was to tear the display apart. (After taking the battery out and unplugging the power of course.) There were several screws under little stick on rubber pads that had to be removed. I then for simplicity's sake unattached the display from the laptop's main body. The LCD has a metal frame around it that had to be unscrewed and taken off. Then it came time to find the bulb. On this LCD display their was a metal housing with the power leads coming out that held the bulb. When I unscrewed this the LCD came more apart then I was really thinking it would. I was unsure of how to get to the bulb, I slowly pulled back the housing and could see it. I detached the housing from the main LCD frame and was able to more easily access the bulb. Using a small screw driver behind the rubber caps, I slowly worked the bulb out from the housing. I then carefully worked the rubber caps off of the end of the bulbs and up the wire. Using side-cutters I snipped the power cables as close to the bulb as possible, (there was not very much slack in the backlight cable from the Inverter to begin with.) The edges of the bulb appeared to be darkened maybe showing their demise. I then stripped off just enough of the cable's insulation to make a loop around the conductor of the new bulb. Once I got the loop at the suggested 2-3mm position from the end of the bulb, I soldered it, and cut the excess wire from the bulb. Slipping on the rubber caps back down made me a little nervous especially with the heavier gage red wire. One of the trickier parts was getting the wires to sit back down right and put the LCD back together. After a few minutes of fiddling and lots of wiggling, I got it to all fit back together. As soon as I did I immediately put a couple screws back in, to keep it from coming apart again. It then came time to test it. I got all the cables hooked back up, plugged back in the power, (nothing blew up or burnt out which was nice!) I then turned it on... low and behold the backlight was still not on! I could still make out the images the LCD was producing, but with no backlight. I then decided to check the Inverter, it appears the Inverter has also gone out, when hooking up a multimeter to the output I got no voltage at all... I will have to check with the laptop's owner and see if they want to put more money into to this aging laptop, I found an Inverter on eBay for $50, so we will see.
And let there be [back]light! After replacing the inverter, the the new bulb came right on and is working great Replacing the inverter was just a matter of unhooking a couple of cables. It took longer to un-package the new inverter then to install it.

8 Comments:

  • Thanks for the helpful information!

    By Anonymous Anonymous, at 8:45 PM  

  • Yeah, thanks for the info! My mom's Inspiron either has a blown backlight or inverter. At least now, I have an idea of what I need to look at.

    Josh

    By Anonymous Anonymous, at 10:58 PM  

  • I'm sitting here with a gateway that belongs to a friend of a friend, and I believe that this is the fix, good to read that someone else ran into it and found a solution. thanks.

    By Blogger Gabe, at 2:33 AM  

  • If you can see a very faint image on the screen but there is no backlight, then in most cases it would be a bad inverter board. From my experience, inverter boards fail much often then backlight bulbs.
    Here’s what I usually do when I have to fix the backlight problem;
    1. Make sure that’s not a stuck lid close switch. When it stuck the laptop “thinks” that the lid is closes and the backlight will never turn on.
    2. Reseat connectors on both sides of the inverter board. Overtime the contacts can get oxidized and reseating connectors can fix the laptop.
    3. If steps 1 and 2 will not help, replace the inverter board.

    These steps should help you to resolve the backlight problem on most laptops. If you are interested, you can find a thread dedicated to troubleshooting backlight problem here: http://www.laptoprepairguy.com
    For those of you who have a Toshiba laptop I have some help too. I’ve created over 50 disassembly guides for Toshiba laptops. Some of them show how to over the laptop case, some of them show how to open the display assembly. If you cannot find your model on my list you still can get an idea how to get inside. Use my guides on your own risk, I publish them as is, without any warranty. You can find them here: http://www.irisvista.com

    Good luck!

    By Anonymous Laptop Freak, at 2:37 PM  

  • I have a Toshiba laptop screen problem but I'm not sure if its the backlight or the inverter. When I turn it on I can only see the screen images if I squeeze and manipulate the frame of the screen. Any clue which area might be causing this?

    Kendra
    K2gem@aol.com

    By Anonymous Anonymous, at 8:15 AM  

  • Great info. I have a HP dv2000 laptop. I have replaced a cracked LCD with a new one. The laptop display was still dim. I replaced the inverter and got the same result. I figured the LCD was bad so I returned it and got a new replacement but the display is still dim. I hadn't considered the close lid switch. Does anyone have an idea where the switch is located on a HP dv2000?

    By Blogger Robin, at 8:38 AM  

  • I also have a dv2000. When I flash a flashlight on the lcd screen, I can see my desktop. Would that be the inverter or backlight? I also just came back from a plane trip (sent my laptop through x-ray) - could that have caused any damage? Thanks

    By Blogger Rachel, at 8:22 AM  

  • whats puzzling on the lower metal strip with the pink and white wires how does it make a complete circuit

    By Anonymous Anonymous, at 6:21 PM  

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