Tried charging via wireless and wired nexus chargers x2 each no indication at all. No battery picture no led's no nothing. Computer will not recognize the device. Held power button for 15 sec., 30sec., 45 sec., 1min. alone, with pwr up, and with pwr down. No status, indication, led, backlight, sound, or any other sign of activity or life. Is there anyone else who has experienced this?