Describe is not a good word, because then people want to tell a story. Sometimes you need the whole story, but usually not.
I also sometimes ask "ok, but what does it do now?" if they start off on a story. The stubborn ones I'll need to lead along.
"ok so what happens when you press the power button?"
"Nothing it's just dead"
"ok, so you doesn't see any lights or hear the fan spins up? "
" yeah, I see the lights and then that big HP screen comes on, but then it's dead and I can't do anything"
"ok so you can't get to the main screen with all your icons? "
" naw, I see that but like when I hit the E icon nothing comes up"
"ok is there an error message or anything on it? "
" yea says something about Internet connection or something "
And then I check it in, flip the wifi switch back on, call them 2hrs later and say it's fixed, and that'll be $49+tax please.