My screen has just gone white and falshes - Apple iPod nano

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Looks like the software just hanged-up on you. Try to reset the Ipod by following the procedures below.

1st option:
Turn the Hold switch on, then back to off.
Press and hold the Menu and Select buttons for 10 seconds (until the Apple logo appears).
You may need to repeat the reset several times.
If the reset doesn't help, then put the iPod into forced disk mode.

2nd option (Disk Mode):
Plug the iPod into a high-powered USB port, let it sit for 2 hours, then disconnect it. If you have a wall charger, plug in the iPod, then follow these steps while it is still plugged in.
Turn the Hold switch on, then back to off.
Press and hold the Menu and Select buttons until the Apple logo appears
Immediately switch your figures to press and hold the Select and the Play/Pause buttons until "Disk Mode" appears at the top.
For a lot of people, this solves the problem. Connect the iPod to the computer and (assuming it shows up) reset the iPod again to get it out of Disk Mode. If at this point you still have the white screen, restore the iPod using the restore function in iTunes under the Summary tab (this will erase everything on the iPod and put it at factory settings).
Note: Do not disconnect or eject the iPod until the store is totally done. After you think it's done, wait another five minutes.

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