defective "one" key
The "one" key has stopped working. This is the key between the tilde and the "2." The "one" key moves up and down normally. I do not feel any abnormality in its action. Left alone, the key remains in its proper elevated position. I do not detect any problem in the key's mechanism. I wonder if there could be a software glitch. But what in the software would disable just one key--I do not know.
Does anyone have any guesses as to why just one key that seems to operate normally does not, in fact, work?
MacBook Air, OS X Mavericks (10.9)