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.
February 21st, 2008 at 6:38 am
kwabena,
If you replaced the LCD, cable and inverter but there is no image on the screen, not even dim image, apparently you have a problem with the motherboard. I don’t know what else could be wrong.
February 21st, 2008 at 6:29 am
Somvir,
Check out the laptop hardware and maintenance guide. Usually you can find error code descriptions in there.
February 18th, 2008 at 11:26 am
Hi guys. can anyone help me out. my hp zv6000 notebook has no display at all. it how ever works fine on an external monitor. i’ve replaced the lcd, cable and inverter but still sohws nothing. its completely black. please help me
February 6th, 2008 at 9:04 am
i have a IBM thinkpad model no. 600E. whan i start it it gives a error massage code 161 and 163.how can i troubleshoot it.
January 31st, 2008 at 7:23 pm
Leonid Syrkin,
The LCD screen is completely black? Can you see a very faint image on the screen? Take a closer look with a flashlight.
If you still can see a faint image, it’s possible that you fried the inverter board and replacing inverter can fix the problem.
Otherwise, if the LCD screen is COMPLETELY black and there is no image at all, I cannot tell you what is wrong without testing the laptop with a known good LCD screen. It’s either you fried something on the motherboard or damaged the LCD.
January 28th, 2008 at 10:47 am
I made a bad mistake during replacement of a cracked Compaq Presario V6000 LCD. I misplaced the ribbon screen wire and after several open/close cycles I saw a lot of smoke and perfectly working screen got black. I took the screen apart and found that the wire got pinched, shorted out and melted. The laptop still worked fine with an external screen though. Then I bought and replaced the wire but did not get any sucsess. The screen is still black while external display is fine. Could the shortened wire danmage the LCD? What else could have happened? I will very much appreciate your advice.
January 19th, 2008 at 12:37 pm
robin,
I would suggest testing the laptop with an external monitor first. If the same defect appears on the external screen, most likely this failure is related to the motherboard or software.
Enter the BIOS setup menu. Do you see the same distortion in the BIOS? If yes, then your problem is not software related.
From my experience, if video distortion appears only on a part of the screen there is something wrong with the screen itself.
Did you have this problem with video before the original motherboard died?
January 13th, 2008 at 2:14 pm
i am fixing a comapq laptop - model v2200us. the motherboard died and i bought a new one from hp. after installing it everthing appears fine except the video is distorted on the right side of the screen. i tried safe mode and the distortion is there as well. the display appears frayed at the edge, the letters are pixelated and slated which looks similar to a frayed edge. This is only on the right side from the top to the bottom of the screen. The colors are fine. I have not yet tried an external monitor but I will. I rechecked (reconnected) the video cable that connects to the motherboard and no change. Could this be a screen problem or a motherboard problem? We added ram and i will remove it to see if that makes a difference. Any help you can provide would be much appreciated.
January 4th, 2008 at 2:44 am
The laptop screen has mysteriously working fine since last 3 days…..It seems that may be some seating problem with video cable was there and it has seated into its place just by normal shocks of handling….please give ur view on this…
nd Thanks a lot for all your help and advice…..
Thanks a lot
Amar
December 27th, 2007 at 12:34 am
ama inder singh,
If external video works fine then most likely your problem is somewhere inside the laptop display panel. As I mentioned in my previous comment, this problem might be related to video cable connection or even bad video cable.
Anyway, I wouldn’t buy a new LCD screen without trying reseating the video cable.