1. Turn off the operating system.
2. Remove all peripheral devices and remove all USB devices and media cards.
3. Detach the AC power adapter
4. Remove the battery
5. Press and hold the power button for at least 15 seconds.
6. To drain any residual power, reconnect the AC power adapter, but do not connect the battery.
7. Turn on the computer.
If this resolved the issue, you do not need to continue troubleshooting.