Hi,
Please do try these troubleshooting steps that may help in solving the issue.
- Start by putting all the original components back in your laptop then boot it up.
- Test the AC adapter next and see if it's supplying enough voltage to power the laptop. Do also try another AC adapter and see if it will power the laptop.
- Do also try to boot the laptop without it's battery and just use the AC adapter and see if it will boot up.
- If all these will not work the problem may lie in the motherboard already.