macOS Sierra slow to accept password at login In the last 2 days, I have found it difficult to login when I start up my mac pro retina. When I try to type in my password, I either have to retype the same letters multiple times or press the same letter key a few times before it is accepted.

I tried NVRAM reset, SMC reset - no different. I tried Apple support via chat and was instructed to set up a new test admin account - same problem remained. I rebooted in safe mode - the issue resolved. So I was told it was best to reinstall macOS Sierra in recovery mode, but the problem persisted after I reinstalled macOS Sierra. 

It would probably be easiest to get a Genius Bar appointment and for an expert to look at my Mac, but I am going away for 6 weeks. Hopefully, I can get by until I return, but if anyone has any suggestions what could be the causes and what else I need to investigate to eliminate the problem, please let me know!
Today I've received my Macbook from warranty due to same problem and they have replaced I/O Board. Issue has been fixed.