This appears to be a hard brick but I'm not sure. I was running 4.4.2 stock, rooted, bootloader unlocked, with Gravity Box, but that's it. Otherwise I've been running normal user stuff and it has been (up until now) just fine, normal battery life and everything.
So the other day I let my n7 die completely, which has happened in the past. Today I went to charge it with my computer and turn it on, so I plugged it into my laptop's USB port. For reference, I just installed Windows 8 and there are no android drivers on my laptop. Anyway, I plug it in and hold the power button and it shows me the google screen, then it goes to a black screen annnndddddddd.... Nothing. It stayed there until I did a hard kill. I can get to the bootloader as well as TWRP. Within TWRP I cleared the caches, and ran a fix permissions. Nothing. I've backed up in TWRP and have yet to wipe my data because that's a last resort for me at this point. Right now its sitting on the charger. When I plug it in I get the battery thing as well as the battery charging thing, however after the battery charging thing goes away I can't call it back up. (usually it'll go away but you can hit the power button and it will come back).