Sometimes, for a random unknown reason, your laptop keyboard might stop working. It's usually down to dust or dirt trapped between the keys, or it could be that the thin membrane material underneath the keys is physically damaged due to excessive pressure. Keyboard also tend to fail if you have spilt any type of liquid on them.
In any case, The Mack Shack can replace your keyboard with a genuine replacement part. The new keyboard, along with the keyboard controller chip on the motherboard, will be tested using industry standard diagnostic software to ensure that every key works when pressed - first time, every time.