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.
If you find this article useful, please consider making a donation to the author. Thank you!
February 10th, 2007 at 7:41 am
Great site and drawing of the laptop!
I have Dell inspiron 8100 that has the equivalent of snow…colored lines with mixed, squiggling color, but still able to read display. The problem comes and goes, unrelated to how long laptop is on.
Can you help? Thanks!
February 10th, 2007 at 12:03 am
how do I reset nvram on a toshiba satellite 1955 with no video post
February 5th, 2007 at 11:08 pm
Carmen,
I’m not familiar with this model but usually you can find inverter inside the display assembly, below the LCD screen. Here’s an example of replacing a failed inverter board on an IBM notebook.
February 3rd, 2007 at 9:41 pm
I got a Dell latitude Cpx I would like to know if you can help me and show me where is the FLInverter on this laptop. I could see the screen but I got to shine a flashlight on it. I hope to hear from anyone that could help me. Thank you.
February 1st, 2007 at 2:58 pm
i have a tiny laptop,It does not charge with or with out the battery the power supply seems ok but im not sure is there any way for to check it thanks
January 31st, 2007 at 12:12 am
[...] Notebook display assembly diagram. How image appears on the screen. [...]
January 26th, 2007 at 12:58 pm
Hi all.!
I have a toshiba a100-906 laptop and I have a strange problem with my guitar and my laptop’s monitor. When i was playing in front of an old crt i had electomagnetic noise to my guitar. When i was playing in front of an lg tft monitor everything was quiet as it should be. today i tried to play in front of my new lappy and guess what…NOISE!! I couldn’t explain what and how and why but after reading about the FL inverter i think that this thing is causing so much noise once again. :/ And i’m afraid that i can’t do anything about it…
Are all those things i say right? Anyone with the same experience?
Thanks
Nikos
January 26th, 2007 at 9:17 am
[...] Originally Posted by dsrtrcr01 OK I found the bulbs. There are 4 of them. IS there a way to test them out of the computer? Just weird to me that all 4 would go out at the same time. Unless they are like christmas lights were if 1 goes out the others wont work? Yeah, you can remove them from the display, plug them back into the inverter and power the monitor up. You are right though, that all 4 of them would die at the same time would be weird. Id probably suspect the inverter or possibly the main board that feeds the power to the inverter. It would be a money gamble to just replace the inverter without knowing for sure. If you have a multimeter, you can test out for dc voltage into the inverter (the multipin connecter). This site below has a picture of what the pins are, as I suspect monitors to be similar to laptop screens. Also, you could try contacting a place to see if they would be willing to test it for you, just send in your inverter and lights, possibly a local place… laptop inverter repair Some more info Laptop Repair Help » Notebook display assembly diagram. How an image appears on the screen. __________________ Roger 05 Tacoma 4×4 TRD DC Off-Road K&N Intake/AEM Filter, XM Satellite, Retrax Tonneau Cover [...]
January 22nd, 2007 at 10:41 am
Hello, I have a dell xps m170 and I am having a problem with the monitor. I was playing some games last night and all of a sudden it went black but it was still on it did not turn completely off (the screen was glowing black not like just a non powered LCD). The computer itself was also still on because I could hear the game sound. It did this twice last night and I let it set for around 20-30 mins and then it would work again. I figured it was due to overheating, but today I was just surfing the web and the laptop had been on for about 5 hours and then it did the same thing again. Now I have not gotten the screen to work. It has a glow but it is just black. I hooked up a normal monitor to it and it worked fine. I ran the diagnostics test and it found no problems but I do not know if that checks the lcd when I have it hooked up to another monitor. Any information would help.
January 22nd, 2007 at 8:08 am
Hi, I have a Dell Inspiron 3800 with scrambled graphics when running WindowsXP. A diagnostic cd tells me it is the fault of the video memory. I managed to order a new graphics card from an online auction site and install it, but it didn’t fix my problem… Perhaps the video memory is on the motherboard (system board)? Does anyone have a resource to find the video ram? I can even tell you the memory address that’s gone bad!
Thanks in advance for any help here.