I've had 2 Notes 4 in my business and for back up for over 20 years and now, FOR NO REASON IS CAN FIND ANYWHERE, have this darend annoying 2 soinning gears problem slowing the boot process whenever I need to put in a newly charged battery, I even tried a Factory Reset on my spare phone, set them up to copy all from man phone to back using the now place back to back until there's a beep or whatever with no beep or whatever. Tried a few time, gave up. The next day, booted the backup and, after the 2 gears, everything had tansferred when I wasn't there; just those 2 darned gears again!! This model served my luxury small passenger service with clients all over the world, for TWENTY years with NO PROBLEMS AT ALL until one day, for nor reason, or was it a simpleupdate somewhere, which I always do manually and decide for myself. I have tried about 8 newer models running higher versions of Android than 6.0.1 but hate the newer OS systems. I wish I ahd a record of the original Android versions on these phones as I'm sure the gear problem is related to the OS now being 6.0.1. If I knew how, I'd regrade the spare to plain v6 and rebuild all my apps manually. I've even tried doing this on the spare after a full reses, with not change.