My Nano 6th is used primarly as a watch. Now I have white screen when turn on (only by pressing both the On and -Vol buttons for over 7 secs). I can get Apple logo to show up at times, but nothing else. It can only turn back to off (black screen) and nothins else seems to show. I can get it to be recognized by iTune on my iMac and restored many times. But still only can see either white screen and or Apple logo. Nothing else seem to be showing. I do have the latest OS update on Nano, iMac and iTune. Any suggestions or help on this will be greatly appreciated.