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:
Fixing notebook video problems.
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April 3rd, 2009 at 1:49 am
is it possible to use my ibm thinkpad lcd monitor to my desktop pc only monitor? How? do i need connectors on it?
March 28th, 2009 at 5:09 pm
Dawn – it sounds like your main display had gone faulty. Displays can often have ’ssections’ that go wrong like that, I have many. Usually it’s because of the screen getting grabbed or being opened by holding just one corner – the display twists & your fault can arrive.
These are not really fixable, and its best to buy another screen for that model.
syazalina – this could be a ‘real’ fault that does need another screen, but it sounds more likely to either be your display settings in Windows (or whatever you are using), you must match the screen ‘refresh rate’ to what your laptop can handle. Not everybody can see these flickers so bad, so get a 2nd opinion on what is being seen.
If your laptop only does this while plugged in, it could be the charger, or battery. Try running it on just mains to check that.
Also, dont use it near other electrical things like a freezer etc. (very rare, but they can interfere on a semi-faulty computer).
Ryan – yes, its essential that all TFT & LCD screens have a good solid connection. The slightest break of connection can mess it all up randomly. It’s also possible that you have a screen that is not matched to the rest of the circuit your using. It can cause slight flicker and fuzzyness sometimes, tho i dont think is your actual problem on your.
March 26th, 2009 at 5:05 pm
I have a dell latitude c600 laptop. When I turn it on there is a line across the middle and the bottom half is grey, but the top shows the top part of the screen.
March 20th, 2009 at 10:25 pm
I have a HP Compaq CQ-40 notebook. The screen display flickers intermittently since the 1st day I bought it. The flickers will be much more when I charge the battery.
Few days ago I sent it to HP Service Center, & left it there for 3 days. They replace my lcd panel & I assumed it was ok after the reapir (I didn’t check whether the problem still persist or not). At home, I found that my laptop is still flickering as usual. This is very annoying. I don’t have time to go to the service centre, besides I really need to use it for my works.
Do u have any idea why my laptop’s screen keep flickering especially when it was being charged. Thanks in advance.
March 4th, 2009 at 3:12 am
my laptop sometime display not coming
February 26th, 2009 at 11:15 pm
nate,
Why do you think there is a problem with the switch. From my experience it fails very rarely.
If you have a faint image on the screen, most likely it’s related to the inverter or backlight lamp.
February 26th, 2009 at 11:13 pm
Rob,
Hard to tell. Could be bad video cable or motherboard problem.
I assume your new LCD/inverter is good.
February 23rd, 2009 at 10:39 pm
I just replaced an LCD w/inverter attached on my Dell Inspiron 6000 and it did not fix the dim screen.. I can barely see the screen. Any ideas what else it could be
February 23rd, 2009 at 7:08 pm
I have a toshiba p205 s6237 and i am trying to locate the lid close switch because the screen is fainted. Do you have a video showing exactly where it is located or how it looks.
February 5th, 2009 at 8:31 am
Ok, I had cracked my dv2000 screen. I just received the replacement and installed it. Now what happens is that the screen flickers, and will only stay on if its just in the right place. I think that this is a matter of some adjustment, but this is my first screen replacement job. One more thing, if I touch the screen it goes off too. Does it have anything to do with the video cable being loose (the original was taped down well)?
Thanks for help.