<human>:  How do I fix a loose doorknob?
<bot>: To fix a loose doorknob, first make sure there are no visible screws that could be tightened to secure it. If there are no visible screws, then you may need to open up the door panel and adjust the screws on the door frame side of the doorknob. If that doesn't work, then you may need to replace the doorknob altogether.