New 3ds and New 3ds XL

I have a New 3DS that does not register buttons, touch screen, volume, or 3ds. The ZL, ZR, and little nub work, but nothing else does. There is no volume, no 3D, and pressing on the buttons and touch screen do nothing. I put in a new right analog stick because thats what I was told was wrong with it when I bought it, but that made no difference. I triple checked all of the ribbon cables, and took out the touch screen for cleaning but it was spotless.

The new 3ds XL won’t turn on. The blue light comes for half a second before going off. I replaced the abxy board with no difference. I checked the ribbon cables and saw someone put one in backwards, but even after fixing that it still won’t come on. It charges and the battery was checked and fine.

I’m not sure what else to try for either of these. Any ideas?