If you have a white screen grey and multiple colored vertical lines in your ipod touch, don’t panic ! The solution is thankfully very simple.
Just connect you iPod to your computer make sure iTunes is up and then hold down the sleep/awake button on the top right hand corner and the home button.
at the same time until you see the apple icon then once u have seen the icon you let go of the sleep/awake button ONLY AND CONTINUE TO HOLD THE HOME BUTTON UNTIL YOU SEE A MESSAGE ON your iTunes that says recognize iPod you going to restore and update once it downloads the software you do the process again and hopefully it will be back to normal.
Make sure u have all of your things backed up before attempting this.