A new iPod nano's diagnostic mode dubbed "iTerm" is revealed, that lets Apple test the living daylights out of your new iWatch touch screen nano. iTerm takes you back to "80′s with a black and greened color display and lets you test your touch screen, radio, headset jack, USB connectivity, and pretty much everything else.
Simply follow these instructions:
Due to changes in its buttons relative to prior Click Wheel iPod nanos, new iPod nano's hidden modes are activated with a slightly different button combination: first, the nano needs to be reset by holding down the sleep and volume down buttons until the Apple logo appears. Holding down both volume buttons during the reset enables Disk Mode, while holding down all three buttons will start up the iPod nano in Diagnostic Mode, briefly flashing the message "iTerm: iPod Display Console" on screen.