Laptop problem

[meenal]

My xps 17 core i7 laptop is not starting up.
on hitting the power button all the lights are getting on but within 5 seconds the laptop is shut down again.
Please help me through this.

 

[Saga Lout]

Try again, this time with the battery out and the main electric supply connected. Sometimes a battery can become so flat as to not even be able to pass power through itself. Dell XPS batteries had a reputation for going down with no warning and charging a little less each time until they ran out completely.