A friend donated me this old laptop, which had a broken LCD. The laptop was old but it worked just fine. I had no intention to spend money to get it repaired, it just would not worth the money. Instead I just removed the screen from the body of the laptop and used the laptop as a HTPC connected to a TV.
Then the screen part was pretty much useless, I could have just trashed it, but I just kept it, just in case I could do something with it. Then I had this idea that I could turn it into something useful.
It turned out that it is very easy, and very useful if you're into drawing. It is a light board/table for drawing, it is very cheap and portable, you can easily carry on your backpack with your books.
Take the old laptop apart, and separate the screen completely off the body of the computer.
Remove the LCD itself from the plastic housing, then start to pry open the metal bezel. There are some screws you need to remove and then some retaining clips.
After removing the metal bezel, you can remove the broken LCD from the rest of the LCD assembly.
The driver board will come off with the LCD.
You will be left with the backlight, try to not touch the layers.
The backlight is made of a lamp CCFL in this one or LED strip, reflective sheet, a guiding glass, some fresnel films, and diffuser films. They have a very specific order, orientation and side. Just keep then as is, or it will be very hard to get then in the correct way later.
Now we will work with the backlight circuit.
This screen have a CCFL lamp, this type of lamp requires a Inverter board to light up. This board is attached on the bottom of the screen, you can just use this original board.
If you have a more modern screen with led backlighting, It will not have a inverter board, you easily make then work as well. You will need to build a led driver circuit, and if you want then to be dimmable a PWM circuit will be required.
Step 6: Inverter board pinout
I reversed engineered the inverter board to find the correct pinout.
What I did was, the board have a controller IC, I looked for the data sheet of that IC and found its pinout description, so I traced where the pins of the connector would go to which pin on the IC.
Step 7: Aditional circuit
To power the inverter board it require 19v, and 5v logic.
So I came up with simplest circuit in order to make it work.
A low power 5volts linear regulator, to provide logic HIGH to the enable pin and a variable potentiometer to provide the analog input to the dimmer IC.
Solder the circuit to a perf board, and test if it work.
Step 9: Fitting everything
After cutting the perf board, make sure it will fit inside the case.
Make sure it is not touching any metal, and hot glue everything.
You can mark the tip of the potentiometer with white-out, and touch the bezel to know were to cut a whole.
I used a screwdriver to dig a whole in the plastic and enlarge it with a knife. If you find hard to make a whole in harder plastics, just heat up a screwdriver with a fire, and melt a whole.
Step 11: Glass
I took the broken LCD to a Glass Store and bought a glass sheet of the same size. It was a bit thicker though about 3mm, but I could fit it inside the original lcd assembly.
It was very cheap, about $ 2.50.
Step 12: Feet
Add some silicon/rubber feet on the other side. You don't want it sliding around.
Step 13: Final result
Here is the final result.