The problem that you are facing is a busted flex cable. I'm posting this thread because I have seen in the past week at least 5 people ask what the white screen is, and how to fix it. Here is a video on how to take apart your play: http://www.youtube.com/watch?v=-3n5ZfkqhzE and here is a link to where you can buy a new flex cable: http://www.ebay.com/itm/Flex-Cable-R...ht_1547wt_1185
The only way you can avoid the flex cable damage is to keep from sliding your gamepad in and out all the time. So basically, just try to do it if you are actually going to be playing a game, not just something you do because you are bored.
I hope this helps anyone with that problem!