You can put your iPod Touch in diagnostic mode by pressing a special key combination. The diagnostics menu allows you to run tests on the iPod that can help you troubleshoot and pinpoint hardware problems. iPods without touchscreens rely on the forward and rewind buttons, but with the iPod Touch, you can select the menu options by tapping them with your finger.
Restart the iPod Touch by sliding the power switch off and on.
Press and hold the "Menu" and "Sleep" buttons together for approximately 10 seconds.
Wait for the iPod to reboot. When the Apple logo pops up, release the buttons. Your iPod Touch is now in diagnostic mode.