Late 2011 MBP Keyboard stopped working after being weird for a day - anything I should consider?

[benyben123]

Hi everyone.
So a Late 2011 MBP. I am not expecting much given its age.
It was working fine until yesterday where the keyboard went all crazy (you'd type A and it would come out something else).
I am assuming this suggest that it's not the keyboard mechanism itself, but... idk... logic board?
After a reboot the keyboard stopped working all together. Won't register a single key.
I connected an external keyboard and it works fine! No issues at all.
Touchpad also works fine.
What gives?

Any advice on this?

Thanks you for your suggestions! I do appreciate it.

 

[cmaier]

I had this happen once and the problem was the battery had swollen to the point where it was screwing up the keyboard.