Chosen Solution
I am apparently very hard on my keyboards. I’ve replaced the top case of a 2014 MacBook Air with unresponsive and jammed keys, gave that to my kids and got a 2017. Now that also has keys that broke off and won’t snap back into the clips (tried new keys) and a 4 that won’t go. Is this something that I can fix with just a new keyboard or is a top case again the way to go? Easier to just do the whole top case, maybe?
I recommend replacing the whole upper case. Replacing just the keyboard is a lot harder as the keyboard is held in with pop rivets which have to be forced out and that does not work well sometimes.