The animated graphics topscreen disappeared and apps wont load Why?

I gave my little brothers, my old 3ds after I bought a new one. They didn't tell me exactly what happened, but I am guessing that they dropped it. Anyways, the DS powers on fine and the system recognizes games, but I won't load beyond that. I can't do an update or even open system settings. I looked at cables and ribbons and they all were seated and didn't show any signs of damage. Any suggestions? I have pretty advanced technical and mechanical skills, also if I needed to replace a part through soldering, I would be able to. Anyone who might know what aspect of the motherboard or even if the WiFi board might be causing this problem, I wouldn't think so, but I have seen stranger things before :) Maybe I should just pay the 85 and send it in to be fixed?