Nexus 7 not charging or turning on - ASUS 32GB Google Nexus 7" Tablet with Wi-Fi

you really cant change the battery but if you feel brave you can try to open the nexus up
HOWTO Remove and Replace Nexus 7 Battery

If the port is broken and you only need it for charging the device, consider getting a wireless charging accessory instead:

Finally charging for our multi device world

Hello,
I am very familiar with this problem with the 2nd gens and it is almost always a sure sign that the tablet is not getting enough power to charge up and will not boot. Sometimes this can happen from the tablet not getting used for a while and getting completely drained. The other possibilities are A) the USB charging port is becoming worn out and won't charge or B) the battery is no longer holding a charge, much like a car battery in the winter. Get an original Nexus 7 wall charger and leave it charging through the wall outlet and not a computer, this has more power. If the light is blinking, it makes me think the USB is not the issue, so chances are after an hour or two it will have some life again.

If the battery is too low, you will need to let it charge for a while before you can turn it on.

If it doesn't work after say 30 minutes of charging, here are some more troubleshooting steps from Google:
Nexus 7 won't charge or turn on

Plug it in to give it a full charge. Push the on/off button and hold it in until it turns on. It may take about a minute. I had the same problem with my Nexus 7 because I let the battery get too low and it would not turn on.

Press and hold Volume Down, and then press and hold Power simultaneously until the device turns on.

Hope that helps!

You can try a hard reset. Hold down the power button and the volume buttons at the same time. The device should then power on and you can follow the on-screen prompts.

Hope that helps!

The battery connector in the Nexus 7 (2012 model) is notoriously problematic. Sometimes dropping the device can cause issues that prevent the Nexus 7 from charging altogether. A hard reset may not work. Fortunately, it is quite easy to fix.

However this will void your warranty. Pop the back of the Nexus 7 case open by pushing a credit card or guitar pick or small screwdriver under the edge of the black plastic case. Start from the top and gently pry the case open, working your way around. The back of the case will come off quite easily. The battery occupies the bulk of the left-hand side of the unit, and a group of six wires come out of the top of the battery to a connector on the circuit board. Gently push the plug out of the socket connector, wait 15 seconds, and push it back in. Snap the case back on and plug in your charger. You should now see the battery charge image appear.

Sorry to hear/read this.
First, try get a new charger and plug your Google nexus 7. Suspect a dead battery with no charge left on it.

Otherwise, confirm your charger isn't just lighting up whereas it isn't delivering any charge current to your device.

Next to try if your ac charger is confirmed good is to attempt replacing the battery; at the store, have them insert a compatible/similar battery and then try power on your device.

NOTE:
New batteries at the point of purchase have some charge on them; sufficient to power on your device.

Device not power on, DON'T PURCHASE NEW BATTERY. Obviously, you don't have a power/battery problem.

Device power on, then you either have a battery that has failed or that your device's charging port needs to be serviced or repaired.

Please post update/feedback asap. Thanks