P2715Q, black screen

I do a lot of work from home and needed a larger screen than my Dell laptop. So, I purchased the best (and expensive) monitor to help save my eyes. Unfortunately, it's only worked on two occasions. Technical support takes me through the same routine when I talk with them. Now, I'm stuck with a $650 monitor. It does have a pretty "black" screen. I'd just be content working with a technical person who is doing more than working through a script.

Thanks,

Helpless