lenovo yoga 720 keyboard and mouse not working

Nov 24, 2018
hello, I just got a lenovo yoga 720 15lkb ideapad, it was all good but keybooard and mouse stopped working, also keyboard backlight was off. I updated every driver with snappy driver installer, reinstalled windows and installed driver with driver booster, reinstalled windows and installed drivers from lenovo official support page, but nothing. keyboard and mouse work only for 5 minutes after windows installation, than first the keyboard and than the mouse stop working. when keyboard doesn't work but mouse yes, keyboard backlight is on. when keyboard and mouse doesn't work keyboard backlight is off (for mouse i mean touchpad, and gestures don't work too). i tried to update and reset bios, to set keyboard drivers as lenovo standard keyboard and standard keyboard instead of elan but nothing. any idea? I tried also to click with a pin the "upside down U hole" near the microphone, it only booted to bios. I'm lucky that touchscreen and external mouse work.

Edit: I formatted and reinstalled windows and I've used it for a few hours without installing any drivers and everthing is ok. So it must be a drivr problem.