It sounds like it could be an issue with the switch itself, or how the ribbon cable connects to the logic board. I would attempt to reseat the ribbon cable that connects the keyboard to the logic board first before attempting to replace the keyboard itself. If a replacement is needed you can find one [link|https://www.amazon.com/Replacement-Keyboard-15ARH05H-15ARH05-15IMH05H/dp/B095W3QZ92|here|new_window=true].