Why does my top screen flicker?

My Nintendo 3ds (new xl, not 2ds) for my kid was working fine until the other day, when it fell out of his pocket. He brushed it off and played some Mario Kart. Later he comes to me and says, “My screen is giving me a headache…” and sure enough, the screen is flickering in a barcode manner, like a scan. I’ve looked up answers online and tried overcharge and battery replacement, but nothing seems to work. To clarify, everything but the top screen works, and it still shows, but it’s lost it’s lushness, it’s full color. Please help, I’ve already spent over 200 bucks on it and it doesn’t pull him in like it used to…