If your attempting to JB your iPod, and it's not turning back on, here's the way to get it to work agian. This is assuming your on Windows. Disconnect your cable from the USB port, NOT the iPod. Wait 10 seconds. Plug it back in. You should see a warning that it's not recognized. That's a good thing. Now, press and hold the Standby button (on the top) and the Home button (on the front). Count to 10... by the time you get to 10, the Warning bubble will go away. Now, let go of the Standby button, but make sure you keep the Home button pressed! Count to 10 agian, and your computer will make the sound that a USB device has been connected. Let go of the home button. If the screen isn't white, unplug the cable from your PC, not the iPod... wait 3 seconds, and plug it back in. Your iPod is now working agian, and you may continue your JB, or restore the original firmware.