Since the 5.0.2 update I got a bricked nexus 7...
It was not my fault, and I was out of warranty so I got pretty upset... and decided to go ahead by miself trying to repair it!
My nexus wouldn't go past the "google" logo, and after some online search I was convinced that it was a nand problem, and that the motherboard had to be repaired.
I have a computer science degree, so I'm good with software, but electronics? ...well, I'm not good at it :) But I took courage and decided to do it slowly and precisely by following the instructions.
By using (some of) the teardown instruction and some online videos I was able with just a few doubts and trial and errors to extract the motherboard and the two webcams, I then replaced the motherboard by following the reverse instructions and... in less than 30 minutes I was already done and my nexus 7 was back to life in no time!
Expecially if you are not so experienced about this stuff, do it slowly and genlty, follow the instrucitons and if you have some doubts find some online video to clarify it.
Replacing the motherboard is way easyer than I expected, so with a little patience you'll be able to do it with almost no effort.
Go ahead and: have fun!
Phillips #0 Screwdriver
iFixit Opening Tool
Nexus 7 (2nd Gen Wi-Fi) Motherboard