take out the battery and press the power on button for 30 seconds. Reconnect and try to start it.
If no go. Take out charger and battery again. Then unclip the ram ( memory ) and check the black chips for any pin holes or smoke damage. If you have 2 sticks of ram, try one at a time.
If no go. Disconnect the hard drive and try.
Still nothing, put it a way for a week or two. It is surprising how many spring back to life after they have been left for a while.