Here are some other troubleshooting steps that may help.
- First is to try your laptop if it will boot up without it's battery.
- Remove the battery off the laptop then connect just the AC adapter and see if it will boot up and will stay on.
- If the laptop will stay on with just the charger connected that means it's the battery that is faulty.
- But if the same problem will persist without the battery that could mean that the AC adapter is faulty.
- Try a different AC adapter that has the same voltage or the same charger that you have and see if that will work.
- If a different AC adapter will still not work I would suggest opening the laptop and reseat the RAM's.
- Remove them all for couple of seconds then put them back in making sure everything is seated properly.
- If all these will not work another test would be to connect an external monitor and see if you'll get any display from it or not.
- And if all these will not work that could mean that it's a motherboard problem.