can't turn on the nano 6

Did you try these suggestions?

Will not turn on or screen remains dark

• Connect iPod to power for at least ten minutes to ensure that the battery has enough charge to allow iPod to turn on.
• If iPod does not turn on after ten minutes, try resetting the device while it is still connected to power. Reset the iPod by holding down the Sleep/Wake button and the Volume Down button for at least eight seconds or until you see the Apple logo appear.
• If the Apple logo appears on the display, connect iPod to a computer and verify that it appears in iTunes and can play music. If iPod appears in iTunes and can play music, no further troubleshooting is needed.
• If the screen remains dark and will not turn on, then your iPod may need service.

copied from iPod nano (6th generation): Hardware troubleshooting

I have this same problem but one thing though, when I connect to itunes it turns on. Once I disconnect, the screen stays dark and it will not turn on. I have followed all the steps, resetting and have left it charging for over 10 minutes. It only plays while connected to itunes. Maybe Im doing something wrong, I really dont know.