My nexus 7 refused to start up, it was a bit more fiddly to fix than I thought:

  1. Press and hold Power until the device powers on, then immediately press and hold Volume Down (while still pressing Power). You will see the word Start with an arrow drawn around it.
  2. Press Volume Down twice to designate Recovery mode.
  3. Press Power to restart into Recovery mode. You will see an image of an Android robot with a red exclamation mark.
  4. While holding down Power, press Volume Up.
  5. Use the volume keys to scroll to “wipe data/factory reset” and press Power to select it.
  6. Scroll down to “Yes – erase all user data” and press Power to select it.

There, simple!

Without a doubt the nexus has become my favourite piece of tech, to the point where I would consider a new one just to get 3G/coverage on it. While I rarely use my iPad on a bus or train, the nexus 7 goes with me everywhere and would actually benefit from being always online.