Question: If you take something from someone's house like a cell phone, that doesn't work, could you still get in trouble for that?
Answer: Yes. Even if the other person's stuff does not work, it's still the other person's property. It belongs to them. They have the right to control its use and exclude others from possessing it. So, unless you have the owner's permission to take it (or proper authority from the government), you're committing theft. The only reason why whether the property works or not may be relevant would be to determine its value. The value of the stolen property determines how serious the crime is. In Arizona, if the value is less than $1000, then it's a misdemeanor. If it's worth $1000 or more, it's a felony.