Inoperative
/ɪnˈɑːpərətɪv/
Definition 1 of 2
Pro Tip 1/3Literal Breakdown
Think of 'inoperative' as something broken down into parts that can't work together. 
After the flood, all electrical appliances were inoperative.
Pro Tip 2/3Temporary State
'Inoperative' often indicates a temporary condition that may be fixed in the future. 
The escalator is temporarily inoperative due to maintenance.
Pro Tip 3/3Emphasis on Inactivity
Use 'inoperative' to emphasize the lack of activity or movement in a machine or system. 
With the power outage, all conveyor belts remained inoperative.