Login box not accepting input

Hello timothyfrommidvale,

Thanks for choosing the Apple Support Communities. We understand you're not able to log in to your Mac, and the password window won't accept the text input coming from your keyboard.

To start, have you tested with an external or Bluetooth keyboard to see if that works? Another thing you can try is starting to recovery to see if you can use your keyboard there. Here is how: Intro to macOS Recovery - Apple Support

If you cannot use your keyboard in recovery, we suggest contacting Apple Support for possible hardware issues.

Apple Support

We hope this helps.

Cheers!

When you booted into Safe Mode and reset the PRAM and VRAM, did the keyboard work? Were you able to verify that holding the Shift Key successfully booted into Safe Mode?