You’ve got a 5 year old MacBook Pro 13″ Retina – and suddenly at login you can’t type your password, because the trackpad won’t track and the keyboard won’t type. Resetting the SMC or the VPRAM doesn’t do anything. You’ll need to replace the trackpad cable that connects the logic board to the trackpad. It’s a well-known/reported user complaint that Apple has never officially recognized. There are a bunch of tutorials on the web that will walk you through the process. The cable is less than $10 and more than worth it to extend the computer for another few years. The only addition I’d make to most tutorials is that once you remove the original cable, use it as a guide to “kink” the new cable since it’s longer than necessary. You’ll kink it once near the logic connecter and another near the connection under the trackpad. That’ll give it the proper length as well as accounting for any swelling that happens with the battery.

Speaking of batteries – I recently replaced the battery (not difficult, just stressful) as well as upgrading the SSD to a 2TB (super easy).