[reed9999]

Observed:

As of an hour ago, I was using my Nexus 10 normally. Power was around 12% so I recharged it, leaving it unattended for maybe an hour. As soon as I picked it up and disconnected it, I heard a little three-note tone I'd never heard before, got a Powering off message, and it shut down.

Upon restarting it I get a Google splash screen followed by a splash screen with four colored dots, moving in different patterns (wider orbits?) than the old splash screen I'm accustomed to, and plays the same three-note tone, followed by the word "android" in a different typeface than I'm accustomed to, in all lower case. Sometimes it dies before the android splash screen, although I might have it out of order. Then it seems to die.

I've repeated this process multiple times with the same result. When I attach the power cable I get a "full battery charging" icon.

Attempt at interpretation

These new graphics make me think it auto-installed an OS upgrade, which is fine, but I can't get it to start. I don't think it's a dead battery because of the battery icon.

I have no idea how to troubleshoot the boot sequence. Can anyone help?

I'm new here so I hope there's not an FAQ about asking for help that I missed.

[Rukbat]

At 12% charge, a 1 hour charge might give you an additional 0.1%. Plug in the charger and leave it alone (and off) at least overnight (preferably 24 hours). If it doesn't boot up then, make another post to the thread. (Use a Reply button.)

The SoC (state of charge) indicator is an approximation - it measures the under-load terminal voltage of the battery, not the state of the battery's charge. It can be far off in certain situations, so don't depend on it when it gets below about 30%.

Unless you can't help it, never allow the battery to get below 40% unless you're conditioning it (which you don't have to do unless the tab has been sitting unused for 6 months, at least).