Bottom half of 3ds xl not working except power button

i have a 3ds xl that a customer brought to me and the bottom half (touchscreen, d-pad, abxy buttons, or home,start,select) of it is not working except lcd and power button. i opened it up and everything looks like new. i tried reseting all cables and now i only get black screens on top and bottom but power button is blue. screens dont flash indicating one of the screen ribbons is not all the way in, battery has been charged all the way up, i blew out game slot, unplugged and replugged the wifi adapter....now im stumped?? HELP ME!! LOL