XPS 15 9550 With Black Screen Issue

Hi,

  I have a  XPS 15 9550 UHD, 512GB SSD and using the laptop without major problems for  3 days. Today I have tried to boot into safe mode for windows and pressed the F8 button randomly on the start. It didnt work and i have retried the boot. I might have randomly pressed the Function buttons like F5-F6-F7-F8 etc.  But right now the the screen is always black, no signs of any Dell Logo or bios login. I can see that there is power on the notebook, fans are working, there is lights on the keyboard but the screen is black and there is absolutely no signs of boot.

  I also have press and hold the FN + Power button. It didnt work. I have tried everything but its not booting. What could be wrong here? Is removing the battery ( I hope the warranty will not be void if i open the backside of the laptop ) and retry the powering on a good idea?

  BTW I have purchased this laptop in US and return to my country Turkey. Is the DELL warranty valid Internationally?

Best regards