Try the following and see if it will charge and start up after.
1. Disconnect the power cord.
2. Remove the battery.
3. Hold the power button for 30 seconds.
4. Now plug the power cord back in.
5. If it starts up, put the battery back in.
If this doesn't work, you may need to test the charger cord, to make sure it is working correctly, as well as check the battery to see if it needs replacing.