Black Screen every 5 -10mins
It really sounds like an issue related to graphics.
I am NOT saying to do the following, I just want to tell you what I would do. I would uninstall then reinstall the graphics drivers. Then try the game again. If that failed I would back up the entire computer and re-install the operating system and start from scratch. This has never failed me. I have my entire system compartmentalized for OS reinstalls that it is a breeze at this point.
Im getting these black screens too. It never happened before 27.01 patch so i dont think its a videodriver problem or so, becouse i havent updated my videodrivers few month and i never get a black screen last year and a half im playing gw2.
You havent updated your video drivers in a few months? Try updating them.