MacBook Pro Retina (13-inch, 2015) keyboard and trackpad unresponsive As in the title. I can only work with mouse and keyboard via USB/BT. Built-in keyboard and trackpad are unresponsive during the boot, login screen nor in OS. Tried: SMC, PRAM reset, safe boot, 3rd party service. 

Surprisingly that tricked worked 2 times in a row: Remove Existing Wi-Fi Preferences in macOS Sierra

I have no clue - nothing was spilled onto it, it just stopped working and becomes responsive very rarely (apart from the trick described above). I want to avoid keyboard/trackpad/board replacement.
It seems the trackpad cable is a potential cause, due to it rubbing on the back cover as demonstrated in this video: https://www.youtube.com/watch?v=aPFCIE0U1ew&amp;t=26s