Bottom screen all of a sudden black but touch works after reassembly

I bought a used for repair 3ds xl that didn’t read games, but everything else worked and both screens worked. Found out that the game reader part had been burned up or something because it was pretty mangled. I disassembled it to unsolder the messed up piece and solder in a new cartridge reader piece. At first, I didn’t take the mother board off, but accidentally burnt a plastic piece where a screw went. This is my first time doing this type of thing, so obviously making mistakes. So I unhooked all the ribbons and unscrewed the board, finished soldering the new piece on and reassembled. Now, miraculously I successfully installed the reader and it will read cartridges, but the bottom screen all of a sudden is black but responsive with backlight. I checked the ribbon cables and the little plastic bracket that snaps on the ribbon still seems fine. I’ve tried cleaning it, but nothing helps. I’ve checked around and it seems somehow I messed up the LCD screen even though all I did was unhook it and re-hook it in. Is that the only fix?