Do still see lights on the laptop or from the AC adapter? If you do try a hard reset, remove the battery and AC adapter then press and hold the power button for 20 seconds. Plug just the AC adapter then power it on, if it does boot up you can connect the battery as well. If it doesn't boot up try and reseat the RAM, remove them all then put them back in after couple of seconds making sure that they are well seated.
If there's no light on either the laptop or the AC adapter, there few thing you do as troubleshooting step for it. Either test the AC adapter if it's supplying enough voltage to your laptop using a multi tester or try another AC adapter that has the same voltage with yours. If all these doesn't work it's the motherboard that is faulty and you'll need to contact the manufacturer if it's still under the factory warranty for a repair.