A3114 Trackpad and keyboard not working

I have a MacBook that won't turn on (1).


I replaced the UF500 and UF400, and it worked perfectly.


I have another MacBook A3114 that won't turn on (2)

When I wanted to swap the motherboards and tried them in each other's chassis, I was surprised to find that in the first chassis (1), the trackpad and keyboard no longer worked.

In the other chassis (2), my motherboard (1) did the same thing: the trackpad and keyboard didn't work.

So I ordered another trackpad, ribbon cable, and another keyboard, but I'm getting the same result.



Where do you think the problem is coming from?

Inspect the connectors and their traces.
There may be mechanical damage.

Okay, let's see about that. When I reassembled it the first time, I lost the backlighting, so I replaced the UP700 and it worked perfectly.