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).

Here’s an example of a laptop with white screen. When you turn on the laptop, it starts but the image on the screen is completely white right from the beginning. In my case it was a Toshiba Satellite M45 laptop but this problem may occur with any other brand.

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.
These laptop service manuals and disassembly instructions may be useful.

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 witch 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 (connector 2) and the inverter board (connectors 3 and 1). After that you connect another working screen and test video.

For this purpose I’m using one of my test LCD screens. My test screen is cracked and because of that you see a wide white band in the center but it still works fine for this test.
The original screen is white but my test screen works normal (except the crack of course) 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.