Hi my name is ***** ***** I will be the expert working with you today to help and resolve the problem you have posted.
I am sorry to hear that you are having such trouble. I will try my best to help you out and resolve the problem as quick as possible.
is the model Ideapad S400?
can you explain the problem a bit more in detail about the keyboard.
did you make and changes on the settings or ran any windows update?
Do you have a small KB backlight icon on your spacebar?
press FN + SPACE together the back-light with turn on if this model has a back light function.
let me know if you have any question.
good that means it has the function
Press and hold down the Fn key and then hit the space bar once it should lit the back-light.
I hope I’ve provided the information you were seeking. If you have any question feel free to ask. Please provide a rating for the service, effort and the time by clicking on the stars located in the upper right corner of the page. Thank you
Is there anything else i may assist you with?