Can you tune a selected communication radio at the CNC while the backup control panel is powered off?

The selected communication radio cannot be tuned at the Centralized Control Panel (CNC) while the backup control panel is powered off because the communication systems rely on specific operational interfaces that function when all control panels are operational. The CNC provides primary control and monitoring capabilities for the aircraft's radios. If the backup control panel is powered off, the necessary circuits and systems that allow for tuning and control are disabled, which inhibits any ability to tune the communication radio. This design ensures that the backup control panel remains functional and can take over seamlessly in case of a failure in the primary systems, but it does not allow for redundant tuning functions to operate independently if it is not powered. Thus, without power to the backup control panel, the tuning capability is compromised.