iPod Touch won't play music or videos I have a 2nd generation iPod Touch and I can't get it to play any media files. Everything else seems to be working fine on it, it just can't play music or videos.

For instance, when I tap a song in the music app, I see the "Now Playing" view for about 1 second before it goes back to the list. It's as if the song started and ended in .01 seconds. But no music ever starts. Whether I have earphones plugged in or not, nothing plays.

When I trying to play YouTube videos or iTunes Store song previews, I get errors like "This movie could not be played" and "Could not play preview".

So far I've tried a hard restart, resetting all settings, erasing all content and settings, restoring in iTunes (EDIT: w/o restoring from backup), restoring using DFU mode. None of these things have worked. I would appreciate any other suggestions. Thanks!
When you restored the iPod did you then put the backup onto it restoring it back to how it was before? If so restore it again and set up as new. Past doing this you're out of options and it would point towards a hardware fault.