In this post I explain how I test the LCD screen inverter board in a laptop computer.

The screen inverter failure is very similar to the backlight lamp failure. In both cases the screen gets very dark and the image on the screen becomes very faint, barely visible under a bright light.

If you suspect the inverter board failure, I know only one reliable way to test that. It’s either replacing the inverter board with a known good one and see if it works, or connecting a known good backlight lamp and see if your presumably bad inverter lights it up.

In most cases I go with the second method – testing the laptop with a known good backlight lamp. Why? Because backlight lamps are pretty much universal. The same backlight lamp will work with many different inverters as long as they have matching connectors. I’ll talk about these connectors later.

The inverter board is located inside the display panel under the LCD screen. In most laptops you can access the inverter board if you remove the LCD screen bezel. The inverter board has connectors on both ends. The left side of the inverter is connected to the LCD cable. The right side of the inverter is connected to the backlight lamp which is mounted inside the LCD screen. Check out this display diagram.

To make sure that inverter board is getting power from the motherboard (via the LCD cable), you can test it with a multimeter. In my case I connected the “+” lead of the multimeter to the pin 1 on the connector and the “-” lead to the ground trace around the screw hole. I got about 19.4V DC on that side of the inverter, so it’s getting power from the motherboard.

WARNING! If you accidentally short something on the inverter while testing it, you can damage the inverter or even the motherboard. Proceed on your own risk! Not sure? Don’t do that!


So, the inverter is getting power from the motherboard, but the screen is still dark. Apparently, it’s either bad inverter or failed backlight. Let’s test it with a known good backlight.

Here’s what I’m going to do:
1. I will unplug the LCD screen from the right side of the inverter. Basically, I’m unplugging the LCD backligth lamp which is located inside the screen.
2. I will plug in my known good backlight lamp which you can see on the picture below. Please notice that my test backlight lamp is shorter than the screen, but for the test purpose that’s OK.

Results I’m expecting:
1. If my test backlight lights up, the backlight lamp inside the screen is bad and there is nothing wrong with the inverter board. If that’s the case, you’ll have to replace the LCD screen or replace the backligth lamp (which is not easy at all).
2. If my known good backlight lamp stays dark after I turn on the laptop, most likely we have a faulty inverter board. If that’s the case, you’ll have to replace the inverter board and it’s relatively easy.

There are two different types of backlight connectors, you can see them on the picture below. The top one (big) is not as common as the bottom one (small). I do most of my test with a backligth lamp which has a small connector.

IMPORTANT! If you decide to buy a new backlight lamp for test, you have to make sure that the connector on the lamp matches the connector on the inverter. Very often backligth lamps are sold without any wires attached. If you plan to use this backlight as a test equipment, you’ll have to find one with wires as I have on the picture 3.

You can buy a cheap backlight lamp with wires here.

Finally, when you ready to test the laptop, unplug the LCD screen from the right side of the inverter.

Plug in your test backlight lamp and turn on the laptop.

In my case, the backlight lamp lights up, so the inverter board works properly.

Check out my previous post about troubleshooting laptops with backlight failure.

 

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128 Responses to “How to test LCD screen inverter in a laptop”

  1. 1
    Israelinkvm Says:

    Hi CJ.

    I love your blog, there’s a lot of tips that i’ve used to repair some laptop, thanks for that.

    I have a problem with a laptop, when I turn it on, the screen is very dark, with one very very soft image, at first, I think it was the lcd inverter, I’ve changed it with no success, the screen keeps black, I’ve read your post and followed the steps to test the inverter with another backlight, when I do this nothing happens, the lamp doesn’t turn on, what this could be??, maybe the motherboard isn’t sending power to the inverter to turn on the lamp??please, I need your help. Thanks.

    Note: When I plug an external monitor there’s no problem, video is ok.

    P.S. Sorry for my english :(

  2. 2
    cj2600 Says:

    Israelinkvm,

    I have a problem with a laptop, when I turn it on, the screen is very dark, with one very very soft image

    Does it look like there is no backlight at all or it looks like the backlight works but the brightness is very low?

  3. 3
    Israelinkvm Says:

    Like I said before, I’ve tested with another backlight but it doesn’t light up, the brightness is ok. :(

  4. 4
    inquirer1 Says:

    hi,what should be the voltage settings for multimeter if I would test the inverter?thanks.

  5. 5
    chakra Says:

    Hi,
    Thanks a zillion for this article. I had a dim LCD screen laptop. By following some of the instructions I could zero in on the problem. I tested out the DC part of the inverter board, I was getting around 15V, but I tested the AC section of the board (the other end feeding the backlight) on a multi-meter and I did not get a reading. So i could figure out that the inverter board was the problem. Replaced the inverter board and LCD screen lights up. Gave me a lot of satisfaction, kudos mate … great job of writing up the article in a very lucid manner.

  6. 6
    cj2600 Says:

    chakra,

    I tested out the DC part of the inverter board, I was getting around 15V

    That means the inverter is getting power from the motherboard.

    but I tested the AC section of the board (the other end feeding the backlight) on a multi-meter and I did not get a reading.

    I don’t think that you can test the AC output with a multimeter, at least it never worked for me. I tried testing the AC output on a working laptop, just to find out what readings I should expect but as soon as I connect the multimeter, the backlight shuts off. That’s way I suggest testing a faulty laptop with another known good backlight lamp.

    So i could figure out that the inverter board was the problem. Replaced the inverter board and LCD screen lights up.

    I’m glad it worked for you.

  7. 7
    cj2600 Says:

    inquirer1,

    what should be the voltage settings for multimeter if I would test the inverter?

    When you test voltage coming to the inverter from the motherboard, you should set your voltmeter to test DC in the range somewhere between 0-50VDC.
    I think you should expect readings somewhere between 10VDC-20VDC, it depends on the model.
    You cannot use the voltmeter to test the AC output.

  8. 8
    cj2600 Says:

    Israelinkvm,

    I have a problem with a laptop, when I turn it on, the screen is very dark, with one very very soft image, at first, I think it was the lcd inverter, I’ve changed it with no success, the screen keeps black, I’ve read your post and followed the steps to test the inverter with another backlight, when I do this nothing happens, the lamp doesn’t turn on, what this could be??

    If the screen has no backlight and replacing the inverter with backlight lamp doesn’t help, apparently there is a problem with the motherboard.

    Also, this problem could be related to the video cable, but it’s not a common failure. If you have the lid close switch – a small button which turns off the light on the screen when you close the display, make sure this button moves freely. A dirty lid close button might get stuck inside the case and the laptop “thinks” that the display is closed even when it’s open.

  9. 9
    Bobinator Says:

    You can also use a cheap electricians amp-meter that measures induction via the magnetic field to test these. The coil creates a pretty hefty magnetic field.

  10. 10
    cj2600 Says:

    Bodinator,

    You can also use a cheap electricians amp-meter that measures induction via the magnetic field to test these. The coil creates a pretty hefty magnetic field.

    Yes you can but I believe you’ll get positive readings only if both the backlight lamp and inverter are in a good working condition. The magnetic field will be created only if the inverter is loaded, right? But what if one of the parts is faulty and there is no magnetic field around the inverter? How can you tell if it’s a bad inverter or backlight lamp?

  11. 11
    AJ Simkatu Says:

    I have a Dell Inspiron 1501 laptop where the LCD goes black at apparently random times after being turned on. The computer remains on and apparently continuing whatever functions it was working on, but the monitor is dark. Sometimes it will only stay on for a minute after bootup and other times I can use it for 10-20 minutes before it goes dark. I am pretty confident its not a battery issue and it shouldn’t be a hibernation or sleep issue, since I am always actively using the computer when this happens.

    I’ve seen other people on the internet with similar laptop complaints, but I can’t seem to pinpoint a common cause. Could this be a bad LCD inverter?

  12. 12
    Dan Says:

    To AJ Simkatu (comment 11),

    I have a Dell Inspiron 1501 laptop where the LCD goes black at apparently random times after being turned on. The computer remains on and apparently continuing whatever functions it was working on, but the monitor is dark.

    If you still can see a very faint image on the screen even though the backlight is off, most likely your problem is related to the screen inverter. If you replae the inverter but the problem is still there, apparenlty it’s a faulty backlight lamp.

    Sometimes it will only stay on for a minute after bootup and other times I can use it for 10-20 minutes before it goes dark.

    Again, sounds like either bad inverter or backlight.

    If you have to guess, I would try replacing the inverter first.

  13. 13
    JH Says:

    I have a screen thats is really bright and everything is washed out, Mouse pointer is only visible if it stops moving and fades in and out slowly when you stop and start it.
    Laptop works fine through a VGA connection.
    This a screen problem?

  14. 14
    cj2600 Says:

    JH,

    I have a screen thats is really bright and everything is washed out, Mouse pointer is only visible if it stops moving and fades in and out slowly when you stop and start it.
    Laptop works fine through a VGA connection.
    This a screen problem?

    Yep, to me your description sounds like a problem with the LCD screen.

  15. 15
    sami Says:

    HI,
    I’ve changed a broken screen of my laptop, but i get a dark screen with faded images whenever i turn it on ,i tried to test the inverter input and i got 1.85 v at start then it goes down to 0.48v after a few seconds ,the cables and connectors are all well connected and when i connect my notebook to an external monitor it works fine, can u tell me plz whats the problem and how can i solve it, thank u

  16. 16
    Bobinator Says:

    “”Yes you can but I believe you’ll get positive readings only if both the back light lamp and inverter are in a good working condition. The magnetic field will be created only if the inverter is loaded, right? But what if one of the parts is faulty and there is no magnetic field around the inverter? How can you tell if it’s a bad inverter or back light lamp?”"

    An inverter takes a (relatively) high amperage low voltage signal and turns it into an extremly high (KV range) low amperage (mA range) signal. There are 4 failure points; CCFL, Inverter, Cable, and Mobo. Couple of things to keep in mind:

    A: If the CCFL fails it will not load the inverter, so no mag field.

    B: If the Cable fails (pretty much it can only fail one way), no voltage = no mag field.

    C: If the inverter fails, you may or may not get voltage; if the CCFL is loading the inverter and the inverter is not producing enough voltage you’d probably not get a mag field.

    D: If the mobo fails, no voltage or not enough.

    Say the unit is DOA and you *THINK* it has a backlight issue, the ampmeter is the 3-second solution to see if you’ve got a functioning inverter. Most laptops go through a power-post procedure similar to a desktop psu and will load the inverter if it passes even if the unit fails to post.

    I like the idea of ordering a $15 CCFL and using that to test; I hadn’t thought of that before and come to think of it to test this properly you’d need an assortment of CCFL’s and cable converters. It’d be easy to build a professional soluton from epoxy, wood, 2×3’s, plexiglass, some screws and a label maker.

    I do keep a spare 12” LCD on hand, as well as a 20” chassis with an inverter hooked into it. You can load a high-end inverter with a low-end LCD ccfl. The problem with either is if you use a 12” LCD CCFL to test a 16” inverter anbd the 16” inverter is ok producing voltage for as 12” ccfl but not a 16” ccfl you wouldn’t know it until you plugged it into the 16” ccfl.

  17. 17
    Rui Says:

    Hello i have a fujitsu siemens with geforce 6800 and my screen show many pink spots and when i twist the computer it get better, but on external monitor the image is always very good.
    Do you have an ideia of what could it be? Many thanks

  18. 18
    pj Says:

    sounds just like my laptop turn it on goes for about 1 or 2minute then goes black. computer is still working in want program it is in . when i turn it on the screen has a pink tinge to it.

  19. 19
    Cameron Says:

    Hi CJ,

    Thank you so much for your thorough review! It is very helpful!

    My Inspiron 1520 has recently had random backlight failures in
    which the screen goes dim. It always re-lights if I sleep and resume (or whenever I start an external monitor). The backlight stays on for a few minutes and then fails again.

    Does this sound like a failing inverter or could there be other explanations?

    Thanks again!
    Cameron

  20. 20
    Dave Says:

    I had computer in rain. Screen is still quit legable with some distortion of images. I ruled out motherboard and video card. So I thought it was the screen. I ordered new one hooked up the inverter to backlight backwards. Some sizzle then went dark. I then installed connector properly and screen lit up fine, but image is still garbled. Did I ruin new screen or ids the problem lcd cable. Thank You.

    Dave

  21. 21
    Nathan P Says:

    I have an issue with my laptop that I think is connected to the screen inverter. all the white colors (only true white, off white is fine) turns into this pink color with white lines and all the black (True black) turns into this green flashing color. if I move the screen about it some times gets better or worse but sadly my screen case is broken so I have to prop it up against pillows. Is this simply an issue with my screen inverter or with the wires, and is it fixable or not? can you recommend a good repair shop is Boise, ID that won’t tell me to get a new laptop? thank you for your time.

  22. 22
    Brian Says:

    What if the screen comes on for a while then goes out. It does the same with an external monitor

  23. 23
    moteldanny Says:

    i just split the soymilk on my laptop, while i didn’t get a chance to shut it off, and right now, when i open my laptop, the screen is very dark, but i can still see a little,very very dark, do you think it is inverter problem or it is motherboard’s….

  24. 24
    cj2600 Says:

    moteldanny,

    i just split the soymilk on my laptop, while i didn’t get a chance to shut it off, and right now, when i open my laptop, the screen is very dark, but i can still see a little,very very dark, do you think it is inverter problem or it is motherboard’s

    There is no way you can tell without testing the laptop with a known good inverter board. If you spilled milk on the keyboard (not display), probably your failure is related to the motherboard.

  25. 25
    cj2600 Says:

    Brian,

    What if the screen comes on for a while then goes out. It does the same with an external monitor

    Can you boot to the desktop or it fails before the laptop finish loading Windows?
    Enter the BIOS setup menu and wait. Does it fail in BIOS?

  26. 26
    cj2600 Says:

    Nathan P,

    all the white colors (only true white, off white is fine) turns into this pink color with white lines and all the black (True black) turns into this green flashing color. if I move the screen about it some times gets better or worse but sadly my screen case is broken so I have to prop it up against pillows. Is this simply an issue with my screen inverter or with the wires, and is it fixable or not?

    Your problem is not connected to the inverter board. The screen is bright and you can see it, so the inverter works properly.
    I think it’s either bad video cable or LCD.
    You said, you can make it better or worse if you move the screen. I think your problem is connected to the video cable. I would try replacing the cable first.

  27. 27
    davd Says:

    I have a Fujitsu LifeBook C Series computer, and it is having intermittent problems, that I believe to be in the inverter. I’m looking for a opinion from more experienced folks. Every once in awhile (usually after having been off for a while), the screen will go out, literally. It will freeze the image on the screen and warp it while it goes out. Simply moving the screen on its hinges fixes the problem and puts the LCD right back where it should be – in perfect looking condition. It may take up to 3 or 4 hinge movements before it finally comes back. I’ve never not been able to bring it back. The inverter is located directly under the LCD.

  28. 28
    davd Says:

    also, it’s pretty worthy to note that the inverter itself gets very warm while in use. I checked its temperature and it was up to 102 Fahrenheit, I’m thinking that is abnormally high for inverters.

  29. 29
    Davey Says:

    It’s got me beat and I hate that. Any ideas would be appreciated. Daughters laptop she says thinks her brother might have dropped it, no visible damage. Screen very dark. Changed power settings to never turn off screen when on mains. Then changed bios to default. Additional monitor works fine and is cloneing laptop screen. Gets 15v from motherboard so changed inverter. Next changed backlight. Both backlights have 16k ohms resistance which seems reasonable. Updated virus definitions and ran full scan. Can’t think of any logical reason why it doesn’t work? Can you help me be a good dad?

  30. 30
    Han Ching Says:

    my notebook is toshiba L300-P502 got one problem, i cant think about what happen. when i pluged-in ac adapter while the battery full charged. the screen brightness might gone up and down flickers itself. until i turn off the ac power, the problem gone. what is the problem?

    if i plug-in ac only sometime it may damn dark and bright dark and bright. the damn dark and bright dark and bright gone if i press Fn+F6 / F7, sometime i on for 4 hour without a problem. even the battery installed. damn notebook just 1 month old, my birthday gift after saving for 2 month to buy it.

  31. 31
    partik Says:

    sir i have a dead laptop i want to use its lcd on my pc how can its posebale

  32. 32
    jakett Says:

    hello CJ,

    I have a Toshiba m45 laptop. The screen has a native resolution of 1280 X 800. When the laptop is powered on, it only displays a 1024 X 768 resolution. This also happens in setup screen also. The image occupies the top left of the screen with the rest being black. I’ve tried connecting a known working lcd screen with same results. When an external monitor is hooked up it functions with a 1280 X 1024 resolution which is the native resolution of the external monitor. Therefor i presume that the on-board video works. Could this be a bad cable or bad on-board video?

    Any suggestions would be greatly appreciated.

    thank you!

    JakeTT

  33. 33
    shawn smith Says:

    Hi, I have a Gateway 7510GX the screen back lite flickers, dims and often goes out, you can still see whats on the screen when it goes out. I was thinking that it was the inverter bord. I dont have a good board to test it with. What do you think?
    Thank you for your time, Shawn Smith

  34. 34
    Matt Says:

    Shawn Smith,
    Do a search for that on google. I fixed my gateway 7510gx with the same problem with just a hot melt glue gun. worked like a charm. There is a tutorial on the web on how to do it.
    Matt

  35. 35
    Omar Says:

    Hello

    I have a PCG-K33 vaio that i need to repair, the problem is that when i turn on the laptop i can see the logo of vaio and even if I enter to the bios setup I can see everything as normal, but in the momemnt that windows starts the back light goes off. I tried to reinstall windows but same issue goes off int he middle of the installation. And the video card is working because if i connect the laptop to a monitor I can see everything and If i get closer to the screen i can see the images but really realy dark.

    What can i do? do you think that is the Inverter or the Lamp Light?

    Thanks for your help

  36. 36
    John Doucette Says:

    My son dropped his Gateway notebook. The LCD cracked. I removed it and order a replacement screen (actually 2). I installed both, but neither screen worked. I connected to an external monitor and everything worked.

    Could I have received two bad replacement screens? or should I assume the inverter or backlight need to be replaced??

    Thanks for any and all advice.

    John

  37. 37
    Mary Ann Says:

    I have a Dell Inspiron 1720 with Vista. If I just turn it on, I get a message to press any key to boot from floppy. It will only boot upcorrectly when I press the F8 key as soon as the DELL logo appears. When I ran diagnostics it gave error code 0322 and said the error was in accessing the LCD inverter. As long as I boot from the F8 key my LCD screen is fine, sharp and clear. It does not fit the description of a bad lcd inverter. Does anyone have any suggestions?

  38. 38
    Vincent R. Says:

    This is great info. I’m a PC tech who does a lot of work for a lot of clients (sometimes I think too many).

    I often left the LCD repair up to guess-work (whether it was the inverter or the LCD itself). For the most part I guessed (or deduced it correctly), but those ones I guessed wrong on were costly and time consuming mistakes I know I could have avoided.

    I used to work with a group of technicians who would hoard their knowledge and never share what they knew with other techs. Needless to say nothing got done very well in that shop, I’ve since struck out on my own and have been doing very well.

    Your little blog was very well written, informative and extremely helpful. I thank you for sharing your knowledge.

  39. 39
    lukas Says:

    Dell model no:pp01s lobtop power on and off when tested power 18.5v shows be in components all matherboard.doide 330j12 has no power.

  40. 40
    paul h Says:

    Hi,
    Nice site to stumble upon.
    I have a Laptop here with a strange problem.
    its a Toshiba Equium m50-164 and the screen brightness seems to be backwards.
    the Fn key for brightness works backwards so up is for lower and down is for higher.
    now the problem that creates is that the screen brightness will not go up full (as the button is meant for darker and wont darken enough to fully turn off the inverter)
    any ideas??

  41. 41
    Ronald Says:

    i have a Fujitsu Siemens laptop, water poured on it i was able to dry it up and have it working but the voltage to the LCD inverter is 1.7 which i know should not be so, this has made my back light not to work, i will like to know what the possible back light voltages are so if i can tap from a point in the laptop to have it work. i am running a 14.4v batt.

  42. 42
    Jeff Says:

    Hey, thanks for the GREAT info. Please dont ever get rid of this site.

  43. 43
    PaulQ Says:

    Hi, found this site a number of months ago and regularly use it as a reference point, keep up the good work. I would be interested to know how i can test if the inverter is getting the required voltage from the motherboard? I am sure this must be possible but i am inexperienced in testing electronic components.

  44. 44
    cj2600 Says:

    PaulQ,

    I would be interested to know how i can test if the inverter is getting the required voltage from the motherboard? I am sure this must be possible but i am inexperienced in testing electronic components.

    You can test the incoming voltage with a multimeter. When you take a look at the inverter side oriented to the cable (not LCD backlight), you’ll see a few a few connectors.
    One of them could be marked pin 1. You’ll have to measure voltage between pin 1 and ground. It could be somewhere between 10-20VDC.
    Be very careful, do not short the inverter with the voltmeter.

  45. 45
    PaulQ Says:

    cj2600

    thanks for responding to my query it looks like i misread the article above as your advice seems to be the same as was mentioned. Apologies!! I would also be interested to know how to trouble shoot problems with the incoming power i.e. i have seen laptops with faulty dc jacks which i have resoldered and still did not work is it possible to test the board at a given point and determine where the fault may lie or would you need a board schema?? Perhaps this could be a subject for a future article??

    Regards

    Paul

  46. 46
    Larry Avent Says:

    I want to know if a bad inverter or floresent tube can give low
    brightness (about 20% to 25%) I can adjust the brightness with
    color settings and get it passable but the laptop (QOSMIO F25)
    should be quite bright!
    I have orderd a new inverter but I just wanted to pick you brain.

  47. 47
    gentlefoot Says:

    Fantastic instructions – very clearly written with nice photos. It’s been really helpful to me. Keep up the good work.

  48. 48
    James Brogen Says:

    Great test, saves lot of trouble and time and takes the guess work out of it.

  49. 49
    mauricio Says:

    dear,
    mauricio’m writing here from Brazil, I think its very good this site for people who are having problems in their notebooks, congratulations and grateful, I have a similar problem with a dell, sometimes the backlight turns on the sometimes not, sometimes which binds and because the place connected to external VGA external monitor, but when I disconnect the external monitor it’ll turn brown,

    I hope your answer.
    Thank you for teaching my teacher.

  50. 50
    AL POE Says:

    Great reading I’ll tell you,,here’s my story on a Dell 1501 the lcd screen won’t apprear until a couple of hand slaps on the left rear of the screen and will then only stay on with slight pressure supplied by my hand on the left bottom corner pulling towards me. This works in any postion of the screen and once the pressure is release it slowly fades to white and other colors. What is on the left side that would do this,,a bad ground or connector. I going fix this some way,,,Please help me.

  51. 51
    cj2600 Says:

    AL POE,

    here’s my story on a Dell 1501 the lcd screen won’t apprear until a couple of hand slaps on the left rear of the screen and will then only stay on with slight pressure supplied by my hand on the left bottom corner pulling towards me. This works in any postion of the screen and once the pressure is release it slowly fades to white and other colors.

    I’m discassing LCD failures in this post. I think your failure is similar to the example 7.
    I would say you have a faulty LCD screen and it has to be replaced. Apparently there is a bad solder joint somewhere on the LCD controller board and when you apply some pressure on the screen you temporarily fix it.

  52. 52
    cj2600 Says:

    mauricio,

    sometimes the backlight turns on the sometimes not

    Can you see a very very dim image on the screen when the backlight is off? It’s possible you have a faulty inverter board.

    sometimes which binds and because the place connected to external VGA external monitor, but when I disconnect the external monitor it’ll turn brown

    I do not understand this part of the description. The external monitor turns brown?

  53. 53
    Eduardo Says:

    Hi!, i got a problem like that
    I have an Acer X193w and it turn normally but in 2 seconds the light turn Off and i can see the image, its kindda screensaver..
    can you help me?

    PS: sorry about the bad english bro
    Thanks!

  54. 54
    Matt Says:

    I have replaced the lcd and the inverter on a gateway mx8738. I am going to try the multimeter test later this evening to see if the inverter is getting power. My screen now will only show a faint image. I dont have a lid closed switch, but was wondering if this computer has a magnetic switch and if so how would I test it or find it? I have also changed the lcd cable out but still nothing. When I boot the computer without an inverter connected at all it does the same thing as if it was connected and bad, dim screen. Any other things I should check before parting out this laptop?

  55. 55
    catalin81x Says:

    Hi, I have a problem with a laptop, Dell D830 when I turn it on, the screen brightness is ajustable with “Fn key” at night is OK but at day the brightnes is to low. How i fix it???

  56. 56
    Stefan Says:

    I have a similar problem with my Desktop LCD, a LCD Flatron W2242T.
    The bottom half of my screen is dark and has light spots right at the bottom, whereas the top half works perfectly. I was considering buying a new screen which wud set me back $300 = =”
    but this site has given me hope, maybe i have a faulty backlight at the bottom. Any advice on what i should do?
    thanks guys

  57. 57
    Jesse Says:

    Could the bulb and the inverter board go bad at the same time?
    I sent the new inverter board back and ordered a new LCD screen. When I put the new screen in it’s still dark! I’m guessing they were both bad and now I’ve got to reorder the inverter board…

    Thanks for your help!

  58. 58
    waligi Says:

    Hi everyone,really need help with my compaq MA8.
    when turned on,nothing appears on the screen and the touchpad lights up only for a few seconds and then goes back off.After that,nothing happens and any key combination given does not even give the usual beeps after.
    I would appreciate any suggestions,thanks

  59. 59
    cj2600 Says:

    waligi,

    really need help with my compaq MA8.
    when turned on,nothing appears on the screen and the touchpad lights up only for a few seconds and then goes back off.After that,nothing happens and any key combination given does not even give the usual beeps after.

    1. I would test the power adapter. Maybe the adapter is dead and the battery doesn’t have enough power to start the laptop.
    2. Check memory modules, make sure they are properly connected to the motherboard. Try reconnecting memory. Try removing modules one by one and test the laptop with one module at a time. It’s possible that your problem is related to memory.

  60. 60
    cj2600 Says:

    Jesse,

    Could the bulb and the inverter board go bad at the same time?
    I sent the new inverter board back and ordered a new LCD screen. When I put the new screen in it’s still dark! I’m guessing they were both bad and now I’ve got to reorder the inverter board…

    It’s possible but not very likely.
    1. There is a chance that one of the new parts is defective.
    2. You didn’t connect them properly. Try reconnecting parts.
    3. If you replaced both but still experiencing the same problem, it could be related to the motherboard. I cannot tell what is wrong without looking at the laptop.

  61. 61
    cj2600 Says:

    Stefan,

    The bottom half of my screen is dark and has light spots right at the bottom, whereas the top half works perfectly. I was considering buying a new screen which wud set me back $300 = =”
    but this site has given me hope, maybe i have a faulty backlight at the bottom. Any advice on what i should do?

    I believe desktop LCDs have two backlight lamps inside ( I could be wrong).
    Apparently one of the backlight lamps in your monitor is bad and has to be replaced. Cannot help you with that. I work only with laptops.

  62. 62
    hannahtuk Says:

    I have a Dell Inspiron E1705 with an WXUGA+ display. I accidently closed the laptop screen cover when a pen was still sitting on the keyboard. Since then, about 1/3 of the screen (on the left side) is dimmed. It never gets really dark, but it’s definitely dimmer (and harder to see) than the rest of the screen, which looks normal. The transition in brightness is gradual – there’s not a clear “line” separating dim from normal. The image is otherwise fine – just dim in that left section of the screen. Is it a inventor problem? or backlight problem? or do I need to get a new lcd screen to fix it? Help~~~

  63. 63
    cj2600 Says:

    hannahtuk,

    I have a Dell Inspiron E1705 with an WXUGA+ display. I accidently closed the laptop screen cover when a pen was still sitting on the keyboard.

    It’s very common.

    Since then, about 1/3 of the screen (on the left side) is dimmed. It never gets really dark, but it’s definitely dimmer (and harder to see) than the rest of the screen, which looks normal. The transition in brightness is gradual – there’s not a clear “line” separating dim from normal. The image is otherwise fine – just dim in that left section of the screen. Is it a inventor problem? or backlight problem? or do I need to get a new lcd screen to fix it?

    I don’t think that your problem is related to the inverter board because the rest of the screen is still bright. Apparently, you’ve damaged the backlight lamp inside the screen.
    That means you’ll have to replace the screen.

  64. 64
    hannahtuk Says:

    :’( That is too bad… It is the most expensive part! :’(
    Thank you very much for your reply. I now for sure know what to buy then. Thank you!!~

  65. 65
    tony Says:

    .

    does inverter or the backlight problem cause your screen to be black permanently if not replaced?

    I have a problem with my old laptop screen – sony grx series – that doesnt seem to turn on eventhough everything else seems to work fine. I can only get the screen to turn on only if i remove and reseat the ram or “shake” my laptop a couple of times.

    is this indication of an inverter or backlight problem?

    .

  66. 66
    farooq Says:

    hi
    dear
    i study y r above page really very intrested
    i have laptop reparing center here in my city
    i have often needs for laptop ics for motherboard
    reparing will y help me for my requrment of ics
    and chip motherboard according requerment
    thanks again and again for such a information
    best regards

  67. 67
    Ron Says:

    I have an HP ze5478cl. the lcd works for a minute goes grey then rolls like an old tv set with vertical hold problems, then comes back. it works fine with an external monitor.

    so , my question is…LCD? Inverter? backlight? which is bad?

    Thanks, Ron

  68. 68
    JLyon Says:

    Hi,love this,it is so informative!
    I’m having a similar problem,but not quite the same as what I’ve been reading & I hope you can help me.
    I have a Dell Inspiron l6400 laptop. Nothing has happened to it, one day I turned it on & the bottom 1/3 of the screen has gone white/gray. There still seems to be light, but can’t see anything. When it 1st started,I could tap the bottom of the laptop it would come back on, but nothing brings it back now.
    I took things apart to check for loose connection to lcd panel. Everything seems ok,no visible damage or anything. Checked the connection,unplugged & plugged the cable back in where it connects by the power button – nothing! Hooked it up to another monitor & dispaly on that monitor is fine.
    Does that mean I need to replace the entire LCD, or could it be a bad cable or something else? I don’t want to spend a lot of $ to replace something & have it still not work!
    I appreciate any advice/help you can give me.

  69. 69
    Tony Says:

    Hi,
    Great site! I have an IBM T30 and came home one day to the screen being dark. It lights up during reboot, logs on to windows and goes black again. I don’t see any faint image, but maybe I need to look harder with a flashlight. The unit has a docking station. I setup an external CRT on the docking station and it works fine. Device manager says everything is fine. The properties tab for display shows two screens inclduing the CRT and LCD. It says the LCD is “not active” if I recall right. I’m wondering if this is a problem with the inverter? The docking station probably has a card in it that is operating the CRT? Also, before ordering an inverter, I can’t determine which one it is. There are two different part numbers out there for my model and I don’t really want to take the laptop apart twice, once to find the number and one to install the part when I get my hands on one. I went to numerous sites, but they just identify with the T30 verus the full model which is a T30 236697U. The two part numbers I am finding out there are: 26P8412 (150nit LCD) and 26P8411 (200nit LCD. What are the nits? I have gone to the Lenovo / IBM site. It only lists an inverter / screen combo pack number for certain models and does not even list this model number. Thanks.

  70. 70
    cj2600 Says:

    Tony,

    I have an IBM T30 and came home one day to the screen being dark. It lights up during reboot, logs on to windows and goes black again. I don’t see any faint image, but maybe I need to look harder with a flashlight.

    Instead of rebooting the laptop, try tapping on the lid close switch – a small button by the hinge. Can you light up the screen when tapping on the switch?
    On some IBM laptop it’s really hard to see anything on the screen when the backlight is off, so look very closely.
    Your descriptions sounds like a problem with the inverter or backlight lamp. Try replacing the inverter board first, they are not expensive.

    Also, before ordering an inverter, I can’t determine which one it is.

    I would find the FRU part number on the existing inverter and use it for buying a new one. It’s not difficult to removed the bezel, takes only 5 minutes. You don’t have to disassemble the entire display, simply lift up the lower part of the bezel, find the inverter part number and put it back together.

  71. 71
    Ron Says:

    Great site!

    I have an HP ze5478cl. the lcd works for a minute goes grey then rolls like an old tv set with vertical hold problems, then comes back. it works fine with an external monitor.

    so , my question is…LCD? Inverter? backlight? which is bad?

    Thanks, Ron

  72. 72
    antoine Says:

    Great site!
    I have a related problem with my 5 year old dell latitude d810. The screen is now dark and the image on the screen is barely visible but still working. Everything else works fine. Shortly before this problem, the screen started to flash when I opened windows or was slightly pink. Your site (and others) seems to indicate that this may be the inverter or the back light of the lcd. I have looked at your other post on the backlight, but does the way the problem occurred tell me something informative about its cause?

  73. 73
    cj2600 Says:

    antoine,

    I have a related problem with my 5 year old dell latitude d810. The screen is now dark and the image on the screen is barely visible but still working. Everything else works fine. Shortly before this problem, the screen started to flash when I opened windows or was slightly pink.

    Most likely the pinkish screen is related to the backlight lamp failure, not the inverter failure.

  74. 74
    David Morgan Says:

    Just to say abig thank you for putting this up, I thought it was excellent and it has helped me in resolving the issue of the backlight I have with my Toshiba Equium Laptop.

    Props to you.

    Dave

  75. 75
    faysal Says:

    Hi i am facing a problem i installed new invertor in my dell laptop decause of old one is not working but my display keys function i,e Fn + Arrow keys not working i also fomate my hard disk with new partition installed Windows Xp.
    Pease help me how i can enable Fn keys funtions.

    Quick response highly be appreciated.

    Thanks

  76. 76
    cj2600 Says:

    faysal,

    Hi i am facing a problem i installed new invertor in my dell laptop decause of old one is not working but my display keys function i,e Fn + Arrow keys not working i also fomate my hard disk with new partition installed Windows Xp.
    Pease help me how i can enable Fn keys funtions.

    I’m not sure why the Fn key doesn’t work. Did you reinstall all factory drivers and software after installing XP? You can install it from the CD or download from Dell website.

  77. 77
    sanjay dey Says:

    Boss,
    from where i can get the company service manuals and repairing guide with flow chart for laptops of all brands, pls help me

  78. 78
    faysal Says:

    Thanks,

    No im not installing factory drivers i have to find out then istall all
    i want to ask that this keys are not working because of new invertor ? or some driver problem ok first i intalled drivers then lets see it is enable or not.

    Thanks a lot again
    Faysal

  79. 79
    cj2600 Says:

    faysal,

    i want to ask that this keys are not working because of new inverter?

    I don’t think so. If the screen lights up the inverter is working properly.
    I guess you are missing a piece of software controlling the Fn key.

  80. 80
    Tamal Says:

    Hello. My notebook Samsung R50 has its some left portion of it more darker than the rest of the LCD screen. And overall I have also noticed that my 3 year old this notebook of mine had its overall brightness reduced.
    My question is: is it the CCFL needs to be replaced or is it the inverter gone bad?

  81. 81
    Duane Says:

    I was given a laptop to check out since the monitor was not working. A month ago I concluded the monitor was just shot and needed to be replaced as I was able to get video to an external monitor but got no image on the LCD at all.

    TodayI decided to break it out again to use with an external monitor. But this time I noticed if I pulled the monitor from the top forward (i.e. I pull it as I might close the laptop, But only pull enough until I lose the “slack”) I was able to see the monitor display without the back light. Once I let go, the image disappears. Then if it’s played around with in some other random fashion, I can get the display and back light to work.

    I am wrong to assume that I may just have a wire problem and not an inverter or backlight issue? I took the laptop apart, but I just couldn’t figure out how to get the monitor off so I could take the bevel off it.

    Laptop is a Toshiba A205-S5871.

  82. 82
    cj2600 Says:

    Tamal,

    My notebook Samsung R50 has its some left portion of it more darker than the rest of the LCD screen. And overall I have also noticed that my 3 year old this notebook of mine had its overall brightness reduced.
    My question is: is it the CCFL needs to be replaced or is it the inverter gone bad?

    It’s hard to tell without testing the laptop with known good spare parts, but I think this is related to the CCFL.
    From my experience, when inverter fails the entire screen goes dark.

    The inverter either works and provides power to the backlight lamp, or doesn’t work and the backlight gets no power at all.

    I think the backlight lamp goes bad.

  83. 83
    cj2600 Says:

    Duane,

    I took the laptop apart, but I just couldn’t figure out how to get the monitor off so I could take the bevel off it.

    You’ll find my laptop disassembly instructions at http://www.irisvista.com
    You can use instructions for a Satellite A215, it’s similar or at least very close to Satellite A205.

    TodayI decided to break it out again to use with an external monitor. But this time I noticed if I pulled the monitor from the top forward (i.e. I pull it as I might close the laptop, But only pull enough until I lose the “slack”) I was able to see the monitor display without the back light. Once I let go, the image disappears. Then if it’s played around with in some other random fashion, I can get the display and back light to work.

    Could be bad connection between the video cable and motherboard. Try reconnecting the cable.
    Also, could be defective video cable.

  84. 84
    Duane Says:

    Sweet! I went ahead and tried again and got to all the wires. Disconnected the wires and made sure the monitor cable was connected firmly, and now it finally works again.

    Thank you~

  85. 85
    dsi r4 Says:

    Be for this post i have no idea regarding how to open LCD screen and make repairing of LCD screen .You provide very nice information and fantastic things.I am really glad about this.

  86. 86
    Steve Midwinter Says:

    I have an Acer Aspire 1710 which has gone Black Screen completely , can see no image on screen. all sounds and processes at startup seem OK activity HDD etc and startup, havent tried it on an external monitor but all keyboard Fn F5 ext to switch to int ext monitor have no effect. also strangely on startup seems to be different the WiFi light sometimes not lighting so altho booting has a difference.. have checked manual and trouble shoot but to no avail. beginning to think inverter or lamp but would screen show something? currently bank/black. werd thing is only yesterday (when it was OK) I had been discussing inverters with a mate who’s Tosh had failed.. weird any help guys?
    thanks Steve

  87. 87
    Lay V. Says:

    Hi, my wife’s Gateway T-1625 laptop LCD is acting up. I’ve replaced it once already because my kids managed to crack it. It worked fine for about 2 months but now it’s beginning to flicker and twitch (I don’t know if that’s the right term for it haha!) There are horizontal lines at the bottom and top of the LCD that prevent you from seeing what’s behind them. Sometimes the screen dims and then gradually gets bright again. It repeats this sometimes. It seems to be slowly getting worse by the week. I’ve tested it with an external LCD monitor and everything works fine that way. Do you think I just got a cheap LCD that’s going faulty already? I’ve read your article, which is great btw, and I don’t think it’s an inverter problem since the laptop is still usable other than its annoying. Any help would be appreciated. Thanks and keep up the great work!

  88. 88
    Henry Says:

    A customer left a Dell Inspiron 1520 for a replacement LCD. She told me that she had dropped the computer and the screen in it was shattered. I received a replacement screen, and installed it, but the screen is very dim. The backlight IS working, but appears to be at the lowest possible setting. The function up/down buttons come up on the diplay when pressed, but I still have the exact same brightness whether this is set all the way up or down. I have flashed the BIOS to the latest version, checked the BIOS settings and the screen settings are turned all the way up. Even put them at the halfway point to see if that would allow the screen to change in brightness with the funtion keys. It is still the same no matter what settings I change. I am leaning towards a bad inverter, but most of the inverters I have seen in the past are either bad or good, not in between such as this one. This computer has an offboard video card, Nvidia GeForce 8400 M. Could this card or something with the motherboard be causing this? One last thing worth mentioning, is it makes no difference if using battery, or AC power. Thank you for any help or suggestions that you might have. Will repost if I find a solution.

  89. 89
    Henry Says:

    PS.
    I tested the screen on a Toshiba that uses the same model screen, and there are no problems, so this IS a good screen. Also, and I find this interesting. The screen from the Toshiba DOES NOT work in the Dell. The screen out of the Toshiba is a 154EW08, the original and replacement from the Dell are both 154EW02’s. These screens seem interchangeable in the Toshiba, but not the Dell. I will order a known good inverter today as I would like to keep one in stock for test purposes anyway. Will let everyone know how this turns out.

  90. 90
    Ernest Says:

    Duane i think your graphics card gone, just a little thought :)

  91. 91
    Subrata Says:

    My three-year-old HP Pavilion DV6275US (RP284UA) shows distorted colors (not pinkish hue) on the Windows screen while booting up, keeps on flickering till the desktop comes up and soon after, with a series of horizontal black bands that go from bottom to top, widening all the time, goes blank. No image is visible after that, even with a flashlight. Moving the dislay panel back and forth does not make any difference. I hooked it to an external monitor and ran for hours without a hitch. That seems to exonerate the video card (NVidia GeForce Go 7400, integrated to the mobo). Looks like there could be three culprits 1) the inverter 2) the CCFL lamp 3) the LCD cable (an outside chance) or a combination of two or all of them! A local repair company of repute suggested replacement of the LCD screen that would set me back by Euro 195. I have read your articles with great interest and I think I can handle replacement of the the parts. Unfortunately, I have no way to test the unit with known good spares. Could you diagnose what is wrong and what I should order as replacement? Any help, comment, suggestions, posted on this page, would be appreciated.

  92. 92
    cj2600 Says:

    Subrata,

    My three-year-old HP Pavilion DV6275US (RP284UA) shows distorted colors (not pinkish hue) on the Windows screen while booting up, keeps on flickering till the desktop comes up and soon after, with a series of horizontal black bands that go from bottom to top, widening all the time, goes blank. No image is visible after that, even with a flashlight. Moving the dislay panel back and forth does not make any difference. I hooked it to an external monitor and ran for hours without a hitch. That seems to exonerate the video card (NVidia GeForce Go 7400, integrated to the mobo).

    Looks like the video card is working properly, I agree with that.

    1. Bad inverter board? I don’t think so. When inverter goes bad, you still should see a very fain image on the screen. From your description is sounds like you have no image at all, so it’s not related to the inverter board.

    2. Bad backlight lamp? I don’t think so. There is no image on laptop screen at all, so it’s not related to the backlight either.

    I think it’s either bad LCD screen (most likely) or faulty video cable (less likely).

    Before you replace anything, try reconnecting the video cable connector on the motherboard. It’s located under the keyboard cover, close to the right hinge. Maybe the video cable is not making good connection with the motherboard.

    A local repair company of repute suggested replacement of the LCD screen that would set me back by Euro 195.

    You can buy a brand new LCD screen on eBay for less than $80 and replace it yourself. Take a look here: HP Pavilion DV6275US LCD screen.
    Here are instructions for replacing the LCD screen in HP Pavilion dv6000 series notebooks.

  93. 93
    cj2600 Says:

    Henry,

    A customer left a Dell Inspiron 1520 for a replacement LCD. She told me that she had dropped the computer and the screen in it was shattered. I received a replacement screen, and installed it, but the screen is very dim. The backlight IS working, but appears to be at the lowest possible setting. The function up/down buttons come up on the diplay when pressed, but I still have the exact same brightness whether this is set all the way up or down.

    Go to the device manager and uninstall display adapters. Restart the laptop and let it redetect the adapter (and LCD screen). Doing that might fix the problem.
    Take a look at this post: http://www.asklaptopfreak.com/.....placement/
    The author had exactly the same problem after replacing the LCD screen on his Dell laptop.

    I am leaning towards a bad inverter, but most of the inverters I have seen in the past are either bad or good, not in between such as this one.

    I agree. From my experience (and I replaced hundreds of them), the inverter either work or not. I really doubt that your problem is related to the inverter board.

  94. 94
    cj2600 Says:

    Lay V,

    There are horizontal lines at the bottom and top of the LCD that prevent you from seeing what’s behind them. Sometimes the screen dims and then gradually gets bright again. It repeats this sometimes. It seems to be slowly getting worse by the week. I’ve tested it with an external LCD monitor and everything works fine that way. Do you think I just got a cheap LCD that’s going faulty already? I’ve read your article, which is great btw, and I don’t think it’s an inverter problem since the laptop is still usable other than its annoying.

    I don’t think this is problem with the inverter board. A faulty inverter board cannot cause lines on the screen.
    I think you have a faulty LCD screen (most likely) or there is a problem with the video cable (less likely).
    Just in case, try reconnecting the video cable on both ends, on the motherboard and back of the LCD screen. Make sure both connectors are plugged correctly and secure.
    If reconnecting the cable doesn’t help, I guess you’ll have to replace the screen again.

  95. 95
    cj2600 Says:

    Steve Midwinter,

    I have an Acer Aspire 1710 which has gone Black Screen completely , can see no image on screen. all sounds and processes at startup seem OK activity HDD etc and startup, havent tried it on an external monitor but all keyboard Fn F5 ext to switch to int ext monitor have no effect. also strangely on startup seems to be different the WiFi light sometimes not lighting so altho booting has a difference.. have checked manual and trouble shoot but to no avail. beginning to think inverter or lamp but would screen show something? currently bank/black.

    If the screen is BLACK and BLANK, the problem is not related to the inverter or backlight lamp.
    With failed inverter or backlight you still should see a very faint image on the screen.

    I would definitely test the laptop with an external monitor.
    If external video works fine but nothing appears on the screen, it’s possible you have a failed video cable OR the cable got disconnected from the motherboard.
    1. Try reconnecting the cable.
    2. Replace the cable.

    If both, the internal and external screens do not work, it’s possible that you have a faulty memory module.

    Again, test the laptop with the external monitor before jumping to any conclusion.

  96. 96
    Subrata Says:

    Looks like the video card is working properly, I agree with that.

    1. Bad inverter board? I don’t think so. When inverter goes bad, you still should see a very fain image on the screen. From your description is sounds like you have no image at all, so it’s not related to the inverter board.

    2. Bad backlight lamp? I don’t think so. There is no image on laptop screen at all, so it’s not related to the backlight either.

    I think it’s either bad LCD screen (most likely) or faulty video cable (less likely).

    Before you replace anything, try reconnecting the video cable connector on the motherboard. It’s located under the keyboard cover, close to the right hinge. Maybe the video cable is not making good connection with the motherboard.

    Thanks for your well-thought opinion. Last weekend I dismantled the LCD screen, thanks to your and another website’s step-by-step guide and took out the CCFL bulb. I re-assembled the laptop and left the bezel cover out so as to be able to reach the inverter at will. After making sure that the computer is otherwise functioning normally and I did not mess it up in the process, I connected the CCFL bulb. It lit up immediately, but started making a metallic repeating sound like a key emits when it gets accidentally pressed and remains depressed for a while. After a while the light went off. I kept the computer that way (front bezel removed) and tried the CCFl again just now. It did not light up. Incidentally, I noticed a very dim display on the screen while booting up the first time after removing the CCFL. I am not sure whether subsequent boots were also displaying the dimmed screen or the screen was entirely black. Please advise what you think from this development. Thanks.

  97. 97
    Subrata Says:

    I think I messed up my last post by trying to add your response to my original post. So here it goes again. I have taken out the CCFL light from the display panel, reassembled the laptop and tested the light. The CCFL lit up but started emitting a metallic sound and after a while went off. I tried it later again (the laptop is working with an external monitor and I left the front bezel out to have access to the inverter at will) and found that the CCFL did not light up nor was there any sound. Could you tell me what I should replace? The video cable has been unplugged from the system board and re-seated without any difference in the display; it remains blank. BTW, the first time I booted up the computer with the CCFL outside, a very dim screen appeared but not on subsequent boots. Please advise.

  98. 98
    CJ Says:

    Dell inspiron 1000 screen blacks out when (even slightly) adjusting position of screen towards close or open. The HD LED and power LED stay lit. No HD spin or fan. 3-finger salute does nothing. Can only do hard shut down and power up to revive. I have no problem if I just touch or squeeze the display; only problem when pivoting on hinges or when shaking the desk enough to adjust the display’s position. If it’s open at 90 degrees, for example, and I then open it to 91 degrees or close it to 89 degrees, display and fan shut off. As if sleeping. I exposed the hinges and made sure the sleep switch is not being triggered. Could it be a short in the cable running from the system board to the display? if so, where to get it and how to replace?
    I’d appreciate any thoughts before I send it to Dell hell (recycling center)?
    Thanks

  99. 99
    Daz Says:

    My daughters laptop hp pavilion dv6000 entertainment displays wavey colours/ smudge difficult to discribe but when i plug my desktop monitor in a get a great picture.
    Iv bought a new screen and it looks just the same. Iv uninstallled and reinstalled display adaptors and all still looks the same.
    Any thoughts please please please ??? Daz

  100. 100
    Rnady Says:

    I’ve been having an LCD issue with my laptop as well CJ. Its a Toshiba Satellite M105-S3041. When I flip the LCD screen open it’ll be on from 1 degree all the way up to 15 degree, but after that it’ll turn off. I ended up opening to check the connectors, etc and everything seemed fine. I’ve created a video to show you the issue. The screen works perfectly between 1 – 15 degrees. The monitor output works perfect as well.

    http://www.youtube.com/watch?v=9c8cvbiiBmY

  101. 101
    Andrei Says:

    I had a Dell XPS 1210 for repair presenting following symptoms: when booting i could see the DELL logo but after the screen turn pitch black. After i’ve tried the laptop on an external monitor and the image was good, i opened the screen and tested the backlight(with an replacement inverter). It wasn’t working. I changed the backlight, it was working but ONLY WITH THE BATTERY. When i was pluging the AC ADAPTER i was getting the same dim pitch black screen…so i reached the conclusion that the inverter was bad…replaced the inverter also and everything was working fine.
    Any ideea why the inverter was working only with battery and not with AC Adapter?

  102. 102
    Mack Says:

    It could be possible that the inverter was being overloaded with the extra current from the AC adapter. Laptops usually dim the screen when connected to a battery hence less current. Thats the only reason I could think of.

  103. 103
    neil Says:

    I have a sony vgn-nr38e, you can just make out the logo on start but thats it. I have tried changing the inverter and have pluged the screen in to another laptop to check the back light which is working fine too. Im at a bit of a loss to whats happening, any help would be great.

  104. 104
    tiffany Says:

    please write me back. my fiance just sent me this laptop from japan and the box was damaged and now i turn it on and it goes black BUT i just realized along with this website that if i push on the part of the screen where you show the screen invertor is, i can get the screen to flicker and dim back on. one side is bright and the other is dark… is it posible that this damage is done due to shipping? it wasnt wrapped or really protected. i cant believe the postal service didnt do anything to protect it. im going to take it in to be fixed, now that i know what is wrong and can help them out. i dont know much about computers, but i know how to figure it out and what to do .. but i wont do it myself. haha. i dont want to ruin it even more but please write me back!

  105. 105
    Ray Says:

    I just replaced the inverter in my Dell 640m, and the display is still not working properly. It starts up, displays Dell logo, and then goes black. I can see a faint image on the display if I hold a flash light to it.

    I connected an external monitor for now. When I use the keyboard to switch back and forth between the LCD and external monitor the LCD works for a few seconds, but is very pink.

    Any thoughts?

  106. 106
    LT Says:

    my toshiba laptop problems:

    1) once the ac adapter was plugged in, the laptop screen was frozen with horizontal lines. cant move, cant shut down, no response to alt crtl del. But, if only use the battery without ac adapter, the laptop wil operate normally.
    however, the battery only can use for 1 half hours. therefore, i hv to plug in the ac adapter. once plugged the screen was frozen with horizontal lines. cant move, cant shut down, no response to alt crtl del.

    wat’s wrong with my toshiba laptop?

  107. 107
    Sam Says:

    I replaced a perfectly working, albeit cracked screen, with what I was told was a compatible replacement – the new screen does work but is stuck at about 40-50% brightness and will not change via hotkeys, hardware, software or bios settings. It has 2 settings now and only toggles irratically between them instead of the proper 8 levels. I even transferred the new screen to my original backlight with no change – could the screen have damaged my inverter? It was working fine with the cracked screen so I’m a bit baffled.

    When just the backlight is plugged in, can it’s brightness levels be controlled via hotkeys?

  108. 108
    aaron Says:

    my Toshiba laptop will not start up

  109. 109
    cj2600 Says:

    Sam,

    I replaced a perfectly working, albeit cracked screen, with what I was told was a compatible replacement – the new screen does work but is stuck at about 40-50% brightness and will not change via hotkeys, hardware, software or bios settings. It has 2 settings now and only toggles irratically between them instead of the proper 8 levels. I even transferred the new screen to my original backlight with no change – could the screen have damaged my inverter? It was working fine with the cracked screen so I’m a bit baffled.

    When just the backlight is plugged in, can it’s brightness levels be controlled via hotkeys?

    Is it a Dell laptop?
    Enter the device manager and remove display adapter. Restart the laptop and let it re-detect the adapter.
    Try reinstalling the display driver.

  110. 110
    Imran Says:

    My hp hdx16 1060es screen has gone to black few days before. Then i move the screen upwards and downwards, its come back. Daily i get my screen on with this manner. But last two days before, i played the game “assassin creed” but next time when i powered on the laptop, my screen was totally black. I also tried many times to remove the battery and pushed the power button for a while, but now this trick is also not working for me. External monitor is working well. please suggest me whats the problem with laptop’s screen.

  111. 111
    garryb Says:

    hey thanks for a great tutorial but i was wondering where can i buy one of these back light testers?

  112. 112
    jvan Says:

    My Toshiba P205_S6287 was knocked off a table. It is still working however the 9″ plastic hinge attaching the top (lid) and bottom (base)broke on one side. The wires that go through that part are being pinched as small area of solid pixels appear on the display until I move the lid to a different position. I can’t determine which parts I’d need to fix the problem assuming it’s repairable. I’m concerned about further damaging the display wires opening and closing the lid.

    Parts suppliers are also unsure as one said I needed a LCD cover assembly but another thought I needed a base assembly.
    Your photos are most helpful and explanations clear but I’m stumped on this one.

  113. 113
    mick Says:

    There’s a diagnostic test at startup on my laptop that tells you if the inverter and backlight are working fine. My backlight is out completely doesn’t come on at all but under a bright light i can see mostly it’s just faint. I come across the test by accident i went to start in safe mode but clicked f12 instead and got a choice to do a diagnostics test so did it and it tested everything on the laptop including an heading for the LCD and the tests for it were inverter it passed, backlight passed and graphics passed. In fact nothig failed at all it took about an hour to check everything. The light went out without warning never did it before just went out and hasn’t come back on!

  114. 114
    Rebecca Meyers Says:

    Hello, I have an Acer Aspire 5516. The screen was broken when we received the laptop, but we did not realize that was the problem until it was returned to the Acer repair center and the tech called to tell us it was not a covered item. I have since replaced the lcd screen following your excellent directions. When I turned on the Laptop, it came on great, screen looked good. Yea….maybe 10 seconds, the screen dims out. Now I did some testing and it is NOT as dark as if the backlight is out.
    The screen is now the correct brightness, however if I move the mouse, it dims. I do not know how long it takes for the screen to brighten up, as I have not seen it brighten, I just look and it is OK…This occurs on battery or outlet.
    Any ideas???

    I am going to take the backlight out of the old cracked lcd screen, how do I go about that?

    Thanks again

  115. 115
    Rebecca Says:

    Hello, me again…OK put the old screen back in works perfectly, with the exception of the black area where the screen is broken. So I am gonna take a stab and figure the problem is the new laptop screen! Brilliant right? Didn’t think of it till I wrote the previous post…duh! So I am calling the screen vendor.
    Thanks for all you do!!

  116. 116
    nixon Says:

    Sir,

    I have a Dell Laptop inspiron 630m which i am facing a problem.the system works for a long time but suddenly LCD gets off blank. that time my cd drive works it comes out.and there is power light still working. then i need to switch it off by pressing the power button. Please solve me this problem.

    Nixon

  117. 117
    nicholas Says:

    Hello, I was wondering how one can pinpoint the faulty component, when the laptop had a flickering screen which now blacks out after a few minutes of use (but is visible under strong light). Is it the inverter issue, or perhaps the cables that feed it?
    any ideas are appreciated. thanks

  118. 118
    dsolod Says:

    Hello,
    I am having similar problem but with a little detail. I get the very dull image on the screen only when my laptop (DELL Inspiron 6000) is cold. After running under this condition about 20 minutes and several restarts it begins showing the normal bright picture with NO problems after. Initially I thought that it might be either inverter or back light. Yesterday I replaced the inverter with no results. I am ready to replace the CCFL but now I am thinking that the problem could be something else.
    If it’s a backlight problem then why it is working right now without any failures even when I restart laptop (because it’s warm). If it’s a connection, wire or soldering problem then it should failure from time to time during the work when i bend the screen and even touch the wires.
    Does anybody have similar experience? Please give me a piece of advise! I would really appreciate this because I do not want to go through the CCFL replacing procedure if I am not sure that this is the case.
    Thank you!

  119. 119
    Gerry Says:

    I have a Dell XPS Inspiron Laptop…I have similar problem on my screen like some of the others here. The screen went black 6 months ago but, sometimes booth normally and then a few seconds later…the screen with go black again. I can see very faint image. Through research and reading your advice…it sounds like a bad inverter. I replaced the inverter and it works for 9 hours straight…the next day when I boot the laptop…it’s black again. I can use the laptop using an external monitor…so I know my video card is good. Any ideas/suggestion? Please help. This site is very informative…Thank you so much in advance.

  120. 120
    cj2600 Says:

    Gerry,

    The screen went black 6 months ago but, sometimes booth normally and then a few seconds later…the screen with go black again. I can see very faint image. Through research and reading your advice…it sounds like a bad inverter. I replaced the inverter and it works for 9 hours straight…the next day when I boot the laptop…it’s black again. I can use the laptop using an external monitor…so I know my video card is good. Any ideas/suggestion?

    Maybe you purchased a defective inverter? Did you buy it from a reputable seller?
    I would try replacing it again just in case. It worked for 9 hours, didn’t it?

  121. 121
    cj2600 Says:

    dsolod,

    I am having similar problem but with a little detail. I get the very dull image on the screen only when my laptop (DELL Inspiron 6000) is cold. After running under this condition about 20 minutes and several restarts it begins showing the normal bright picture with NO problems after. Initially I thought that it might be either inverter or back light. Yesterday I replaced the inverter with no results. I am ready to replace the CCFL but now I am thinking that the problem could be something else.
    If it’s a backlight problem then why it is working right now without any failures even when I restart laptop (because it’s warm). If it’s a connection, wire or soldering problem then it should failure from time to time during the work when i bend the screen and even touch the wires.
    Does anybody have similar experience? Please give me a piece of advise! I would really appreciate this because I do not want to go through the CCFL replacing procedure if I am not sure that this is the case

    I guess you can buy a new CCFL lamp (it’s expenisve) and the laptop without installing the lamp into the LCD screen.
    By the way, it’s not easy to replace the backlight lamp at all. I would suggest replacing the entire LCD screen if the backlight lamp is the problem.

  122. 122
    cj2600 Says:

    nicholas,

    I was wondering how one can pinpoint the faulty component, when the laptop had a flickering screen which now blacks out after a few minutes of use (but is visible under strong light). Is it the inverter issue, or perhaps the cables that feed it?

    Most likely this is inverter related problem.
    1. Try replacing the inverter board first.
    2. If no help, most likely it’s bad backlight lamp inside the LCD screen. You’ll have to replace the screen (or backlight lamp inside the screen).

  123. 123
    dsolod Says:

    cj2600,
    Thank you for your reply. Here is the second part of my story. I got the new CCFL for replacement. I connected it to inverter and found it working when the original one did not. Bingo! Being sure that the lamp was the problem I replaced it with the new one on my DELL Inspiron 6000. When I assembled everything back and turned the notebook on I saw the familiar dull image. Whaaat!!! The first thing in my ming was that I damaged the back light during the installation. I disassembled everything back and suddenly it started working again. I tried to find the problem and bended slightly the screen and rechecked all the connection. Sometimes during those tests the lamp did not glow but i could not find the problem. I put everything back and now the laptop is working normally but already I had one situation when I had to restart the computer because of the dull image. I have no idea what to blame. It could be a electrical board on the screen, it could be the screen cable. I do not know what to do to be sure. I do not want to buy the new screen thinking that it might be cable. Could anybody give me piece of advise please?
    Thanks!

  124. 124
    Tim Says:

    Hi, I have a Dell Inspiron 1300, recently the inverter broke. But I can’t find this exact inverter. Si I would like to ask if I can use the inverter with P/N: YPNL-N021A IV12139/T-LF to replace the original inverter with P/N: PWB-IV11145/T/W2-LF?

    Thank you very much for your kind attention and help!

    .tim

  125. 125
    cj2600 Says:

    Tim,

    I have a Dell Inspiron 1300, recently the inverter broke. But I can’t find this exact inverter. Si I would like to ask if I can use the inverter with P/N: YPNL-N021A IV12139/T-LF to replace the original inverter with P/N: PWB-IV11145/T/W2-LF?

    Just search on Google for YPNL-N021A and you’ll find it.
    I would recommend replacing it with the same inverter.

  126. 126
    D Chai Says:

    In regarding to the two connector type you have shown in the picture. Are they inter-changeable? I mean if my original inverter has “big” connector plug into it, and, my newly purchased LCD screen happen has “small” connector at end of wire. Can I simply cut and connect the old one to replace the one on new screen?

  127. 127
    Yamandu Says:

    I would like to know what I can do because the computer that I bought is having a failure, in LCD screen.

    When I start the computer the screen begins to sweep from the bottom to the top, this happens for about 3 minutes, and after that time (about) it gets still and looks normal, although on the bottom of the screen a single line of pixels continuous flickering and changing of color (rose, purple, blue).

    Sometimes also after a while or when starting a new program the failure starts again.

    I updated the Nvdia drivers, tried to change the screen resolution, but nothing changed.

    I tested the computer with an external LCD and the problem disapeared.

    I need to find a solution because it seems to get worse.

    Yours sincerely.

    *Product Type : Notebook
    *Product Model : X83Vm
    *Place of Purchase : USA
    *Date of Purchase : 2009/1/1

  128. 128
    Anil Says:

    hello,
    I am having a toshiba satellite laptop. The invertor was getting too hot below the screen. One fine day the screen went black but still can read under a tube light. I ordered a new screen invertor and replaced the old one. It works and still gets hot. Now after a week the screen again went black again.What could be the reason for the invertor getting hot.
    Please help.
    Regards
    Anil

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