Like its predecessors, the 6th generation iPod Nano has a diagnostic mode used by Apple techs to troubleshoot and test the device, to make sure everything is working properly and to find the source of any problems it may have. Since the newest Nano lacks a click wheel, the method for entering this diagnostic mode remained unknown until now.
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.
From this diagnostic mode, you can test the power, audio, remote, TV out, LCD, I/O, FM radio, memory, touch panel, and accelerometer. If you have Apple’s lastest Nano on hand, try it out and let us know if you find anything interesting.