What is the purpose of using a tone generator in AV system diagnostics?

Using a tone generator in AV system diagnostics primarily serves to verify physical cable continuity. When a tone generator is used, it emits a specific audio signal or tone that can travel through the cable. Technicians can then use a tone probe or similar device at the other end of the cable to confirm that the signal is present, thereby indicating that the cable is continuous and there are no breaks or faults within it. This process helps ensure that the system will function correctly by confirming that the signal can travel from one end of the system to the other without interruption, which is crucial for maintaining the integrity and performance of the AV setup.

While the other choices may be associated with general AV troubleshooting, they do not focus on the primary function of a tone generator as specifically designed for verifying the continuity of cables, making that answer the most accurate and relevant to the question.