Step one is to determine exactly what it is that is making your laptop screen dim.
If your screen is busted and cracked, this ehow is not for you. So, there are three possible things that it could be. The most likely is the backlight went out on the screen and you would have to buy another screen.
The second most likely is that a board called an LCD Inverter is dead. This is pretty common amongst laptops and is actually a pretty cheap and easy fix. Details will be explained.
The last and least common is that your graphics chip on your motherboard is dead or one of the bridges on the motherboard is dead. Most likely this isn't it and I will show you how to tell in a moment.
Ok, now it's time to rule out the motherboard being toast. If the motherboard is dead then here is a simple test to tell. Take a bright light like a flashlight or desk lamp and hold it up to the screen while the laptop is on. Can you see the desktop background? If so, the screen is on but it's not receiving any backlight to light up the screen. So if the screen comes on, your motherboard is good.
So now we are down to the last two options. Either the backlight is dead or the inverter is dead. There is really no sure fire way to determine and in the end it is trial and error. But the good news is that we can try to narrow it down by determining some key factors. Did your screen look discolored or dimmer before it went totally black? Did the screen flicker on and off sometimes then come on for a while before going totally black? When you open and closed the lid did the screen come on and then go back out?
If it did any of these things, it is 80% of the time the inverter. If it just went totally out all of the sudden with no discoloring or flickering, it is more than likely the backlight. So let's learn how to fix it.
First, we will talk about replacing the screen. You need to take apart the screen border to get to the screen. Your screen border should have some little rubber sticky bumpers on it. Remove these to get to the screws. Once you unscrew them, carefully split apart the front and back of the screen border. Keep the screws where you will not lose them.
Once you disassemble the screen border, you should be able to pull the screen towards you leaving the back of the screen border where it is. There should be a ribbon type cable there to disconnect from the back of the screen. Do it. If you screen is screwed into the brackets on the side of the screen, simply unscrew them.
Next, you need to order a replacement screen. In the resources at the bottom of the page, I have listed a great company that carries many screens of major laptop brands and models. So when you go to the website, lookup your brand and model of laptop and you should get a list of screens that are compatible with it. Purchase one and when it gets to your house install it by putting the ribbon cable back in it and screwing everything back together. Then if it was your screen and not the inverter, everything should work. Now let's learn how to replace the inverter.
The inverter is easier than the screen. Take off the screen border and right below the screen, or sometimes on top of the screen, you will see a little board. There should be 2 wires connected to it. Disconnect these and take the board out. There should be a part # somewhere on the board. Go to google and type in replacement inverter board laptop make and model goes here* and hit enter and it should pull up lots of sites for you to search for a replacement. Most are under $50. Once you get it in the mail, just plug the wires back where they came out of and put the screen border back on and turn on your laptop. It should work like a charm. And that's how you fix a dimmed laptop screen. Hope this helped you. If you have any questions, leave a comment.