Does not start up.

The Toshiba Satellite C665D laptop I have does not start up. The light indication comes up when charging the battery and all but as soon I press the power button down all the light (that includes the charging and a/c port lights go off) I am not able to find a solution to this. This started occurring after the dismantled my laptop for cleaning. I also made sure all the wiring are right too, without leaving wires unplugged or so. Can someone please help me out here. ThankYou.