How do you fix an iPod screen that has gone white?

You can hold down the power and the home buttons for about 30-40 seconds.

If it doesn't work, then let it power down completely, then plug in the computer until the charge is complete.

Another option is, to go to iTunes on your computer and wait for the iPod touch to down completely and charge it until it is completly charged, then click restore if it doesn't show up then try both of the above answers, if it still doesn't work take it in to a specialist.