If your laptop's battery is easily removable, you can removing the battery after removing the ac adapter. Then disconnect all the peripherals and the then press and hold the power button for 1 minute. This should release any static electricity buildup that may have accumulated. Then try powering on the computer with only the ac adapter connected.
To add to my previous steps, please share the exact model number for the system so that i have more information to work on. When did the system last power on, also did you try making any hardware or software changes on the system prior to this?