When I turn on my laptop all I get is a white screen

I have a Toshiba Satellite M35x When I turn it on all I get is a white screen. Looks like it’s booting up but there is no display. I hooked up my external monitor and I get a (Windows XP starting up) display when I turn the laptop on then the display on the external monitor goes blank. I just paid $200.00 bucks to have the ac jack adapter replaced.

After you connected the external monitor wait until Windows XP startup display disappears and the laptop screen goes black. On Toshiba laptops you can use a combination of keys Fn+F5 to toggle the video output between the internal laptop display or an external monitor, or to set it to display the image on both screens. Try to press on the function key and then F5 and wait for a while. It might take some time to switch the video output between screens. If you set the laptop to display image on both screens, then you will get a white screen on the internal display and a normal output on the external monitor.
I have seen a white screen on Toshiba Satellite M35X laptops many times. I’ve noticed that very often this problem occurs because the video cable pops out from the connector on the back of the LCD screen. This problem could be easily fixed when you push the video cable back in place. I’m not sure if you want to reseat the video cable yourself because to access it you have to open the display. Here is Toshiba Satellite M35X display disassembly guide. You can see the video cable pictured on the step 7. The connector is located under the yellow tape. Most likely your cable is half-way out and you have to push it back into the connector. Be careful with the connector on the LCD screen.

More laptop video troubleshooting tips.