Computers and Females

Okay, so the joke is playing on the double meaning of "charge her." Like, when a computer is down, you gotta charge it up with electricity, right? But it also sounds like you're charging a fee to a female. See, you probably didn't know this, but you are so dumb that you didn't get it. It's kinda sexist and kinda funny, if you have a sense of humor, which you don't.