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 22 21 20 19 [18] 17 16 15 14 13 … 1 » Show All
December 25th, 2007 at 4:56 am
When I attached it to the external monitor,the screen is perfect,great resolution…so it means the LCD is gone bad…so do i have to replace the whole LCD screen…How much would be the tentative cost of new HP LCD screen…man,I don’t remember any physical pressure or damage to the laptop so how can the LCD screen be damaged.
Waiting for your good advice.
Thanks
Amar
December 23rd, 2007 at 1:20 pm
laura,
First of all I would check the memory module, it could be bad. Try reseating the memory stick, just remove it from the expansion slot and install it back in placed. If you have only one memory module and two memory slots, try moving the module from one slot to another. If you have two memory modules installed, remove them one by one and try starting the laptop with only one module installed. Find out witch one is causing the problem.
December 23rd, 2007 at 1:14 pm
ama inder singh,
You’ll have to test your laptop with an external monitor and find out if you have the same video defect on the external video. From your description I can assume that you might have a problem with the graphics card or video memory.
If both laptop LCD screen and external monitor display same dots and lines, this problem is not related to the laptop LCD. Most likely there is something wrong with the video card or video memory. If the laptop has shared video memory, when a part of the main memory is used for the video purposes, it’s possible that the main memory is going bad. Just in case run memory diagnostics test and see if it fails. You can use Memtest86+ utility.
If video is bad only on the laptop LCD screen but the external monitor works fine, it’s likely that you have a problem with the LCD screen. I would also try reseating the video cable on the motherboard and on the LCD screen, just to make sure it’s not a connection related issue. If the video cable is not making a good contact with the screen or motherboard, you can get all kinds of video issues.
December 23rd, 2007 at 1:00 pm
April Meunier,
I don’t think this is a virus, to me it sounds like a hardware related problem. This laptop is still under warranty, right? Just send it back to Dell for repair.
December 23rd, 2007 at 12:19 pm
heyaa laptop guy .. i have a fujitsu seimens laptop and i was using it all of a sudden a blue page displayed which said errorr……….. then i restarted the computer and discoverd that it had crashed so i switched it off again and left ih however i am now trying to switch it on and deres no display whatso ever on the screen i can hear the drives and everyfing could u please help me .. urgentlyyyyyy
December 23rd, 2007 at 4:25 am
I have this HP Pavillion dv2002tu model,just over an year old anf suddenly yesterday the whole screen has this pink and green dots which seems to be in constant motion at their own place.When a black screen of startup or the cmd prompt is there I see loads of small green dots which are flickering on their fixed postion all over the screen.Also when there is blue screem,evryhtng seems ok as no dots are visible and all white areas have small pink dots like th border of this message window is full of pink dots.Also during startup,I see three vertical green line,one in the center,another on extreme left and 1 cm from the right.
Kindly help….what is the reason..i have restarted it,reinstalled video drivers and formatted HDD..but nthng changes…Do i have to replace the LCD screen…hw much will it cost for 14.1′ widescreen to be replaced.I am from chandigarh,India
Looking forward for a reply…
December 17th, 2007 at 4:29 pm
I have just bought a Dell Vostro 1000 a month ago. I am having problems with the screen turning white and at different times it has blue and white horizontal stripes. It happens about twice a day and I have to restart the computer when it happens. Dell says it is a virus but I don’t have any. They have not been much help.Can you help me please.
Thanks, April
December 7th, 2007 at 4:06 pm
I accidently dropped by 3 month old HP laptop and now the display is gone. I have a old DELL Latitude Laptop, is there anyway I can connect the HP to the DELL display?
Thanks,
Anna
December 7th, 2007 at 6:45 am
Hi,
I have sony vgn-s260 laptop,i have changed motherboard recently,because computer wont’t boot up,now i have new motherboard(second hand) and laptop boot up but no graphic at all.black screen,i can hear that laptop is working hard drive etc.,but nothing on screen,i have even plug external monitor to vga-out ,still nothing no signal,do you think it is a bed graphic chipset on motherboard?thanks
December 5th, 2007 at 7:54 pm
Thanks cj2600. I will try it this weekend. Will let you know if that works. I am also guessing that the backlight lamp from the old screen can be used with the new screen. Thanks again.