Never plug in a random power supply that "fits".
You are lucky at this point if you didn't just fry it dead.
Start with getting the PROPER power supply, then remove the battery and try to power it on with just the power supply, if the screen doesn't light up, try a external monitor, if that works you have a bad screen, back light, inverter board or possibly cable. If that doesn't work, move on to testing ram, pull the sticks out, replace them with known good stick(s) an see if you can get it to run.
Lastly, odds are deffinetely against you that the netbooks power supply was anywhere near powerful enough and probably didn't even output the correct voltage.
Again that was a very unwise decision, never and I mean never do that with any piece of electronics, especially one that runs off DC power.