Rob Pegoraro's post on Android | Latest updates on Sulia
Tip: Don't let a Nexus 7 run down, or you might have to try a bizarre workaround (which might not work anyway).
I was all set to ship a long-neglected loaner Nexus 7 back to Google PR when I realized it wouldn't charge or boot up. Quick Googling revealed that others had encountered the same issue and had found a fix: http://www.droid-life.com/2012/12/27/fix-nexus-7-refusing-to-charge-try-this-trick/
I followed that advice--plug in the Nexus 7, hold down the power and volume-down buttons for about 20 seconds until the bootloader starts, select its power-off option--and thought I'd fixed the thing when its screen finally showed it charging.
But now this Nexus 7 can't get past its own boot logos. It looks like abandonment somehow left the tablet in a catatonic state. And that I may have to amend my earlier endorsement.