Today one of our regulars stopped by the desk to inform me that 'the mouse is bad' on computer #3. I told him I would 'look into it' but all I did was wiggle it around (it seemed fine) and then unplug it and plug it back in. We get a lot of hardware complains that turn out to be user error somehow--they say the keyboard is broken because they're using the number pad without number lock turned on, their lack of experience with a mouse explains why the cursor is just shooting madly around the screen, etc.
Similarly, I have also asked patrons to 'please try it one more time so I can see the error message' knowing that the reason they can't get into the public computer/their email account/their library account is almost certainly that they made a typo in their login information. This one I do almost daily, actually.
My first instinct when I hear that something is "broken" or "won't let me in" is that the patron is wrong. That said, I don't want them to feel like I'm not taking their problem seriously, so I have to make up a way to make them feel like I'm addressing a problem that doesn't actually need to be addressed. It's sort of like a doctor giving a patient a sugar pill so that they will feel like they are being treated and get better--the classic 'placebo effect.'
This even happens with non-technology things. I also do searches for things I know I can't find or won't be available, because patrons want to see you doing that, and don't want to be told "This is not something that will be available." Recently, I did a search for books on 'free grants from the government' on our shared regional catalog, just to prove to the patron that there would be nothing because I knew he wouldn't take my word for it. I also frequently make searches for the personal contact information of celebrities rather than just saying "This person is a celebrity. Her personal cell phone number will not be something I can find." These searches, looking at things from a purely rational standpoint, are a waste of both their time and mine. I've been told that my job is to 'help' patrons, but does that mean wasting their time in a fruitless search or telling them, when they are unlikely to believe me and likely to get angry, that the search is fruitless? For better or worse, I usually go with the former.
I wonder whether doctors ever give patients sugar pills not to actually change the patient's state, but simply to preserve their relationship with the patient. They, like me, probably want the patient to feel like they are 'helping' even when no help is needed or possible.