The trackpad and keyboard both use the ribbon cable, so when it fails completely, both the trackpad and keyboard will stop responding.. With the exception of the power button.
It’s a toss-up if it’s the same issue with only one key being unresponsive. Could just be a bad key. But I’d give it a shot since it’s only a $10 fix with a t6 screwdriver. Or if you want, mail it to me and I’ll fix it and use the laptop as a secondary computer to run my data visualization computations =D