Final answer:
During a preventive maintenance inspection of a sewing machine, it's essential to check for loose or damaged parts, proper thread tension, and the smooth operation of the machine.
Step-by-step explanation:
When performing a preventive maintenance inspection on a sewing machine, it is important to check for all of the above: loose or damaged parts, ensuring proper tension of the thread, and verifying the smooth operation of the machine.
Loose or damaged parts can cause the sewing machine to not function correctly or even become a safety hazard. Proper thread tension is crucial for consistent stitching and to avoid thread breakage or fabric puckering. Smooth operation is essential to ensure that the machine is working efficiently without any hiccups, which can affect stitch quality.