How do I fix my black top screen on a 3ds xl?

How do I fix my black top screen on a 3ds xl?

My 3ds xl's top screen is completely black when I turn it on-botton screen works fine. No damage to screen known, just unresponsive. I noticed theres a slight crack to the casing by the right trigger- not sure if that was there before. Any ideas on how to fix it? Thanks!