Electronics and machinery.
Had to call in our maintenance guy because the elevator wasn't working. He first walked me through the steps for a full reset over the phone, which I followed. It did nothing. So he makes the 25 minute drive over here and proceeds to do exactly the same thing I just did. Bam, the damn thing works.
This is precisely the reason I chose not to go into working on computers, because the same exact solution you've tried before works when someone else is watching, or the phase of the moon is correct, or Venus is in the house of Capricorn or something.
Edited, Jan 31st 2012 6:00am by Poldaran