I have a Samsung laptop and was using it this morning, I stepped away for a few minutes and when I returned, the screen was dark. This sometimes happens and I just lightly tap the power button to get back to work. Today when I did that, it flashed and then the screen went black. The power button is lit up and the charge status light is green. When I hold down the power button to reboot, it does not respond. I usually leave the computer plugged in when I'm home, so I don't know if it's a battery issue or not. It's like it's in permanent sleep mode or something. Is it safe to remove battery to try to reboot? I did this one other time and my hard drive took a dump and needed replaced.
For starters disconnect the power supply, remove the battery and hold the power off/on button in for about 20 secs. See if it works after you have restored the battery and power - it might not but it is quick to try. If some previous computers HD needed replacing it was nothing to do with this type of action - it just happened to have ended its life.
Always pop back and let us know the outcome - thanks