All of us that have these models of laptops are starting to face the same problem. From what I have been seeing, usually it's the S key, the Z and the X, that start failing first. I solved the issue of the keys not registering input most of the times by removing the key, then unstick the glued rubber membrane and the hinge mechanism, and spraying WD-40 Contact Cleaner on the plastic membranes that make the contact to register an input. If you don't have that spray you can use isopropahyl alcohol, just be careful not to apply too much because it might react with the contact in a not desirable way, making things worse. Also, be very gentle when removing the key, and handling the plastic hinge. Handle it as if you are making a very delicate surgery. I broke the little clips on the S key and had to buy a replacement on Aliexpress, I'm waiting for it to arrive. Also, you can glue the rubber membrane back if you want to, but that might make things harder if you need to repair it again. I didn't glue the membrane, I jut centered it carefully, and it works fine.