My top screen will not come on or charge...

So I have had my 3DS since it was out and about 5-6 months ago my 3DS top screen was bugging out but would always go back to normal. The next week my top screen went black and NEVER went back to reg. I tried everything to fix it ( except prof. help ) Exp. I have tried opening it up, letting it sit, and also pushing the power button for 30 seconds. Then it wouldn't even charge anymore. The moral of the story is I just need an explanation or hopefully a solution. Thank-you in advance.