Hi,
Here are some troubleshooting steps that may help.
- Start by doing a hard reboot, remove the battery and unplug the AC adapter then press and hold the power button for 20 seconds then try booting it up again.
- If these will not work do reseat the RAM's, remove them all for couple of seconds then put them back in making sure everything is seated properly.
- If these will still not work, do test the laptop if it will boot up without its battery connected.
- Do also try a different AC adapter that has the same voltage and see if it will boot up or not.
- The problem lies in the motherboard itself if all these steps will not work.