Solved Keyboard Typing Wrong Characters Purchased Off Ebay Like This Macbook Unibody Model A1342

Chosen Solution

I purchased a MacBook off eBay in hopes of repairing it, the description said the keyboard is buggy and types different characters other than the ones you have pressed. I was wondering if anyone could list the possible problems it could have that would result in such behavior.

This is most commonly caused by water damage and you have to replace the top case: MacBook Unibody (A1342) Upper Case To test and isolate the problem, plug in an external USB keyboard and see if the problem persists.