Sorry that I can't help with your problem, but I wanted to ask about the white screen of death.
I'm seeing this I think on my 700IDT. Sometimes there are black lines one pixel wide running across the screen, varying every time it is powered on. Sometimes you can also see that something is showing but just barely. And after turning it off and on a number of times it will finally work right. Same problem?
And check with the mp3car store, they sell parts and may be able to sell you a new touch controller.