Jerry's suggestion is valid. Another thing to try is to hold the power button and shut the machine down. Continue to hold the power button down for a half minute or so, even after shutdown. Restart the machine and see if you see the Samsung logo or anything on startup. If you see the Samsung logo on startup, it indicates that your hardware is likely ok, and you are dealing with a software issue. If you see the logo, then it just goes to a black screen, let it sit for a few hours and see if it comes back. I've seen some situations where Windows gets messed up but it "restores" itself after doing some stuff on startup while there is a black screen.