Notebook display assembly diagram. How an image appears on the screen.
Here is a simple diagram that will help you to understand how a notebook display assembly works and how an image appears on the screen. I’m not an artist and I tried my best drawing this diagram, so if you cannot see a laptop in this picture, don’t be mad. 
A generic display assembly includes a very few parts and knowing them will help you to understand witch part can cause a problem if you laptop video not working properly.
Video cable. A video signal from the motherboard goes to the LCD screen through the video cable. The video cable connects to the motherboard (or video card) through the connector 1. The video cable connects to the LCD screen through the connector 2. The video cable (in most cases) is also responsible for supplying a necessary voltage for the FL inverter board. The video cable connects to the FL inverter board at the point 3.
FL inverter board. This board is responsible for converting low voltage DC power (point 3) to high voltage AC (point 4), necessary to light up the backlight bulb. If the FL inverter board is bad, the LCD screen (backlight bulb) will not light up when you turn on the laptop, but you still should be able to see a very dim image on the screen.
Looking for a new screen, video cable or inverter board? Find it here.
CCFL (backlight bulb). When the backlight bulb lights up, you can see an images on the LCD screen. In most cases the backlight bulb is a part of the LCD screen and if it’s bad, the entire screen has to be replaced. By the way, some specialized repair shops can replace the backlight bulb itself.
Lid close switch. The lid close switch is a small button that locates close to the display hinges. On some newer models there is no button, because the switch is magnetic. You can set up your laptop to go to a hibernation mode or to a standby mode when the LCD is closed. It’s done through power management software. These modes are triggered when the display is closed and the lid close switch is pressed down. If the LCD screen on your laptop will not light up when you open the display assembly, check the lid close switch is stuck inside (it might happen because the switch is dirty).
Related articles:
Troubleshooting and fixing notebook video problems
How I took apart and repaired my notebook LCD screen with water damage - removing the LCD and taking it apart
Screen inverter replacement. Fixing laptop backlight problem. - replacing inverter board in an IBM ThinkPad laptop
Laptop has bad video on the screen. What is wrong?
Entry Filed under: Laptop Tips and Tricks
221 Responses to “Notebook display assembly diagram. How an image appears on the screen.”
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Pages: « 23 … 18 17 16 15 14 [13] 12 11 10 9 8 … 1 » Show All
May 22nd, 2007 at 3:20 am
I have a Sony Vaio PCG-GRZ615 model for about 4 years. I experienced no problems, until yesterday when my LCD screen fickered two three times and then went off. However, I can still see a dim image on my LCD screen. I attached an extranl CRT monitor and everything and it works well. So no problem with the graphics card I pressume.
As far as I leart searching the internet my problem can be either a converter or a CCFL lamp problem.
I opened up the lcd screen and I am wodering the problem lies; IS IT A CCFL or a CONVERTER PROBLEM?
I give you one extra element that might with some extra help. When I press the lid switcher manually with a pen the CCFL light tries to light for a sec (yellow-red color) and then again goes off. This happens every time I press the lid switcher.
I know that when the converter starts working it gives a greater voltage supply for a second. So my question is… if the CCFL lamp was the problem would it flicker at all every time I press the lid switcher or it it will be just dead at all times?
Any suggestion would be appreciated.
Thank you
May 21st, 2007 at 5:37 am
I have the same problem as the guy who left comment 57, but the screen isn’t totally blank yet. It’s just covered with lines. How can I fix it? Thanks
May 20th, 2007 at 2:39 pm
Hello i have a dell Dell Inspiron 1300 but i can,t seen to get it out of stay by mode.
The power light is flashing all the time and three lights on the top.
I have remove the battery and try just the power pack and it still does,nt work.
Even switch the main plug off and on, nothing will happend.
Last night everything was fine but i left it in stayby mode all night. The next day it would not come out of it.
Try pressing the button but no luck.
P.S: Only have a dell power pack now since the battery is dead.
Any help please?
May 16th, 2007 at 8:08 pm
George,
Sorry, cannot give you a lot of help with Dells, I work mostly with Toshiba, IBM and business HP laptops.
I would say the inverter is specific for a particular screen. Both your screens are similar, so I guess both inverters should work. It’s possible the 9400 setup uses a different video cable, that’s why you are getting nothing on the screen with the 9400 setup.
Not sure what is wrong with your laptop but I would try this. Install the 9300 setup back as it used to be. If you turn on the laptop, the Dell logo appears and then the backlight goes off, right? Now unplug one cable from the inverter board (K08I020) - the cable witch goes to the 9300 screen backlight lamp(the data cable still should be attached to the screen) and instead plug the cable with goes to the 9400 screen backlight lamp. In other words you’ll get two screens connected to the same laptop, the data channel still would be connected to the 9300 screen but the inverter board will supply power for the 9400 backlight lamp. Turn on the laptop and check how the 9400 backlight lamp works. If it still turns on for a while and then goes off, I would try to find and replace the original K08I020 inverter, it might be your problem.
It’s just a guess.
May 14th, 2007 at 7:09 pm
Need help. I have a inspiron 9300 with a dim/faint screen. On boot, the dell logo displays normally. Then the screen goes dim. External monitor works fine. Dell diagnostics error is “Error accessing the lcd inverter”. My dell has a philips LCD LP171wx2 17 inch WXGA+ and my inverter board is a K08I020. Dell is no help and wants to charge me $500! Everytime I contact them it seems like everyone is working on commision-Way to lose customers Michael. I purchased a replacement screen with inverter on ebay mistakenly advertised as a 9300, but it is actually a screen and inverter for a 9400-philips LCD LP171wx2 (same screen) and inverter K08I025. When I attach the 9400 setup to my 9300 I get nothing-not even the dell logo. If I swap inverters I get the dell logo again but the new (9400) screen goes dim like the original problem. BTW the 9300 screen is dim including logo with the K08I025 (9400) inverter. So, my questions are:
1. Are these inverters compatable?
2. Do you think it is worth purchasing a K08I020 inverter (cant find any new ones on the internet)?
3. Are inverters specific for a particular motherboard/video card?
4. Do you think my problem can still be the motherboard or video card?
Thanks
May 13th, 2007 at 4:20 pm
Bhupi,
Did you remove the processor during disassembly? If you did, make sure the processor is seated properly and the socket is LOCKED.
May 13th, 2007 at 4:18 pm
Brian,
What did you mean by that? Are you getting errors during the upgrade or what?
Run tests for memory and hard drive. You can use Memtest86+ and Hitachi’s drive fitness tests, you’ll find links on the right side.
May 12th, 2007 at 11:22 am
I have the toshiba M35X…i corrected the power jack problem but the laptop would not boot up now. The blue light on the power switch tuns on but goes off in 3-4 seconds.
After reding the reviews i have opened and closed the laptop 10 times to check all coneecctions and everything looks fine.
could a problem in display monitor other than connections cause it? how can i identify the problem? PLease help…
Bhupi.
May 11th, 2007 at 8:45 pm
I have a Compaq Presario R3000, and a couple of weeks ago I inadvertantly left it on hibernate while I was out of town for a week. When I tried to reboot, it initializes… goes until the Windows XP screen and then starts over..
I’ve tried booting from my XP disk, and that didn’t work.. I tried to upgrade to Media Center, and that didn’t work… So I figure it is a hardware issue.. Somebody.. Anybody PLEASE HELP!
May 7th, 2007 at 5:21 am
applet computer,
If the laptop LCD is still bright and you can see an image on it (even bad image), there is nothing wrong with the backlight bulb or inverter.