When I turn on the computer the screen is white but the computer is booting up.

Laptop LCD screen turned completely white
What can you do if the laptop LCD screen turned completely white? From my experience I can tell that this problem may be related to the following:
1. Loose connection between the video cable and the LCD screen.
2. Defective LCD screen.
3. Defective motherboard (I assume the graphics card is integrated into the motherboard).
When you turn on the laptop, it starts but the image on the screen is completely white right from the beginning.
Most likely you still can use the laptop with an external monitor. Just connect the monitor to the VGA port on the back or side of your laptop and then switch the video output from internal to external mode.
On Toshiba laptops you can toggle between internal and external screens using Fn+F5 keys. Hold down Fn and press on F5 until you get video on the external monitor.
On IBM laptops use Fn+F7.
On HP laptops use Fn+F4.
It’s possible that you have to use a different key combination on your laptop but you get the idea.
On some laptops, in order to be able to use the external monitor, you have to connect it to the laptop and then restart the laptop so the external monitor is detected by the laptop.
I noticed that in some cases the laptop screen may turn white because of poor connection between the video cable and the LCD screen. If you want to check this connection, you’ll have to take apart the display panel because the connector is located on the back side of the LCD screen.
I always check the video cable connection first. Reconnecting the video cable may fix your problem.
If reconnecting the video cable doesn’t help, most likely you have a problem either with the LCD screen or with the motherboard.
The best way to find out which one is causing the problem is testing the laptop with another working LCD screen. Without this test you’ll have to guess because as I mentioned before this could either bad motherboard or bad LCD screen.
You’ll have to disconnect the video cable from the LCD screen and the inverter board. After that you connect another working screen and test video.
The original screen is white but my test screen works normal and I can see the image. After this test I can tell that the problem must be related to the screen.
After I assembled everything back together and connected the original LCD, it’s still white.
CONCLUSION.
In my case this problem is related to the LCD screen and it has to be replaced.

I ran into the same problem a couple of months ago. Luckily my brother has a laptop of the same model. So I tested the laptop LCD to find out that the LCD / connecting wire is not the problem. The motherboard's video chip is damaged. For the time being i am using the laptop with an external LCD monitor.