This morning I dropped my Nexus 7. On the outside it was OK, but it wouldn't power on. The charging animation displayed when I attached the power cable. But nothing else would happen, no matter how long I held down the power button.
First thing I did was look for solutions on the internet. Most people suggested holding the power button for 30+ seconds, which as I already said did not work for me. One person, however, suggested to open up the device because the battery connector can very easily disconnect upon impact.
Since the drop already voided my warranty, I figured I no longer had to worry about voiding warranty so I removed the backplate. I could not see that the indicated connector was disconnected, but I did find another one that was: the connector to the buttons (including the power button). I carefully reconnected it using a toothpick, tested the power button and it turned on again! Turned it back off, re-attached the backplate and turned it on again, works like a charm!
Unfortunately I forgot to take a picture when the backplate was removed, and I don't feel like removing it again, so no pic for you. But at least I'm happy again with a working Nexus 7, plus the knowledge that I successfully fixed a gadget! (I know this is the simplest fix imaginable, but one has to start somewhere, right?)