Hi, I was scrolling through facebook and my laptop suddenly beeped and turned off. I tried to boot it, but I've just got a white underscore (not blinking) and nothing happened, even the manufacturer logo didn't pop up on start. I tried to boot from USB, but same result. I tried to unplug HDD and plugged USB with live Ubuntu and it works just fine. I thought the hard-drive is dead, so I purchased new HDD from second hand with pre-installed windows, plugged into my laptop and same white underscore. I tried cmos reset, trying to switch RAM sticks. Tried to boot without battery, just with AC adapter but still the same. Fans are spinning, I can feel it and hear them. I don't really know what's wrong.