To enter the diagnostic mode on the iPod, first of all reset it. When you see the Apple logo, hold down Next, Previous, and Select. When the Apple logo goes away, release the buttons. You'll see the coolest thing ever: a backwards Apple logo, as if you were inside the iPod looking out. If it's a 3G, you'll hear the iPod emit a little squeal, like you were pinching it. Diagnostic mode contains stuff used by engineers, technicians, and factory folks to test out the iPod. Read more >>