Hi,
Please do try these troubleshooting steps that may help in solving the issue.
- Start with a hard reboot, remove the battery and unplug the AC adapter then press and hold the power button for 20 seconds then see if it will boot up normally.
- If these doesn't work do connect your laptop onto an external monitor and see if you'll get any display from it.
- Next to try if these doesn't work is to reseat the RAM's, remove them all for couple of seconds then put them back in making sure everything is seated properly.
- If these doesn't work as well test your AC adapter if it's supplying enough voltage or try a different AC adapter if it will make the laptop boot up or not.
- If all these will not work the problem would be the motherboard and a repair is necessary.