We repaired our Nexus 7 and it comes on but will no longer accept the security code. What to do?

[AC Question]

The coding numbers are not entering correctly. We type a 2 and it comes up 4!

 

[Rukbat]

What does "repaired" mean? The problem could be a miscalibrated or broken touch screen, a bad motherboard, a pinched cable, a corrupt ROM - too many things to even guess at a solution without knowing what you did.