update drivers.
try external keyboard
format

I did update drivers, I can't find anything how to fix this problem and I seen alot people have this problem.

Whats full model
Does it still occur with exert Al keyboard?

Ideapad Y700 17"

Still haven't answered if it works with an external keyboard.
Also thats not the full model number.

1 Update Bios.

2 " I decided to chat online with a lenovo tech support. He prompted me to enter the Device Manager and under the tab 'Keyboards', uninstall everything (right click and click uninstall). We also did the same with the 'Mice and other pointing devices' tab. After doing so, the two tabs (Keyboards and Mice) disappeared. After restarting the laptop, they were back in the Device Manager Folder, and I haven't had any problems since!"

3 Format

4 RMA

those are your options in the order I think you should do them.