With the laptop turned on and the screen being white, try to squeeze the bezel around the LCD. See if you can find a soft spot that changes the screen back to normal colors.
If you do find such a spot, an easy fix would be to put something (tape/rubber/paper-towel/etc.) underneath the bezel to keep some pressure on that side of the screen.
I understand there's a touchscreen there... Be sure that nothing is pressing against it.
As for the power switch, here's the most intuitive solution I've ever seen:
Laptop remote on/off issue -- SOLVED: s2000 carputer