If you tried everything the only other thing it can be that it's broken. What exactly did you try? Double-check cables and re-connect them? Try them with another source to make sure it's not coming from the computer? Did you contact support for the company that made them?
I also have that problem, but when I use regular audio cable for pc (not the controller thing from the box) speakers work. So I would say that it's a controller thing that's not working, while speakers are okay.