Hi,
Start by doing a hard reset, remove the battery and AC adapter then press and hold the power button for 20 seconds. Plug just the AC adapter then see if it will boot up and if it does you can put the battery back in. If these doesn't work try testing the AC adapter with a multi tester to see if it's supplying enough voltage to power and charge the laptop. You can test the laptop if it's working fine by try another AC adapter that has the same voltage as with yours have. If it boots up normally with a different AC adapter you know your suspect.