Laptop turn on for 3 or 5 seconds and then off

Situation: The user can’t turn on his Laptop. It turn on for a few seconds and then it turn off.

Troubleshooting 1: Perform a power drain

1. Shut down the computer.
2. Unplug the computer from the wall socket.
3. If the battery is removable, remove the battery and hold the Power button down for 15 seconds.
4. If the battery is non-removable, while the computer is ON, hold the power button down and wait for the computer to shut down and still hold the power button down for another 15 seconds.
5. Turn the computer ON and check.

Troubleshooting 2: It could hardware issue. Check Hard disk, RAM connection and motherboard.