Chosen Solution
keys from 1 to 9 and their upper cases not working, started two days ago. Macbook Pro, retina, late 2014. I did: reset SMC, reset PRAM NRAM, reinstalled OS, installed upgrade OS, disabled mouse keys, started in safe mode, did disk first aid repair, started in recovery mode, etc. Nothing works. All other keys are working. Still. Nothing has been spilled, no drops, dirt, etc. I have been using it for a week, the issue started only days ago. The machine looks pristine and has only 17 battery cycles. I am using my keyboard viewer in my language prefs to type this.
Try using an external USB keyboard. If it works, first try reseating your keyboard to logic board cable. If issue persists, replace either keyboard or upper case. See step #25 of this guide: MacBook Pro 15" Retina Display Mid 2014 Upper Case Assembly Replacement
