From time to time my Nexus 7 tablet battery will get drained so low that it can’t be turned on and plugging in the power cord will not wake it or even start it charging.  So now your stuck with a tablet that cant turn on, and cant be charged.  Trying combinations of buttons pressed prior and after plugging in the charging cord failed until I found the right combination.

To charge a dead Nexus 7:

1. Plug-in you dead Nexus 7 to a wall charger.
2. Immediately after plugging it in, press Power and Volume Down buttons at the same time.
3. It may take several attempts till you get the timing sequence just right.  When it works, 1 of 2 things should happen.
   1. The bootloader menu should load, use the Volume Down until you see “Power Off Device”
      • Choose that option with the power button.
      • Once the device is off, unplug the charger and then plug it back into the device
      • You should now see the battery meter (pictured above) showing it is charging
   2. You should now see the battery meter (pictured above) showing it is charging.

I hope this helps you with you dead Nexus 7.  In the future, we should all make sure to not our Nexus 7 completely run out of power.  When you see it get close to 10%, start charging it.