So you would expect the Captain to say....
Ah passengers
"Unfortunately we have a light that won't go out. it's the APU for the SOs USB port. Unfortunately it means a risk that the power won't work to his iPad meaning he can't play Angry Birds all flight... Obviously with your safety in mind we will need to get it fixed.
We will try rebooting it from this end by kicking every panel we can find. If that fails we might have to go back to gate, but we don't know whether the airport has the part, let alone a spare engineer or a spare gate.
Worst case scenario is will have to sit hear a few hours in 50 degree heat, myself and the SO will go out of hours, so we might have to divert to Timbuktu, or we might have to offload and make you sleep in the terminal as there are no beds due to the power outage from the cyclone.
Anyhow we look forward to a good flight, if we ever get off the ground."
Half the time the issue is the unknowns.