Please see this video for some suggestions....
Verify that there is a charging indicator light on the right side of the Chromebook when the charger is connected (usually close to the shift key).
Also, check that:
The charger or adapter cables are completely plugged in, both to your Chromebook and the wall.
The power outlet is working (test at another power outlet if possible).
If your Chromebook still won't charge:
Unplug your charger from the wall and your Chromebook.
Plug your charger back in to your Chromebook, then the wall.
Charge the device for at least 30 minutes.