After applying 10R04 6953:

Not officially. Garmin bootloaders reject older firmware versions once a newer "update upd" has been applied. Rolling back requires a JTAG service tool (dealer only).

If the PC installs drivers but the software won't find the unit, try a different USB port (avoid USB hubs) and ensure your internet connection is high-speed (avoid public Wi-Fi). Rebooting Loops:

You downloaded the wrong 6953 variant (e.g., for marine vs. automotive). Fix: Delete the .upd file, re-download using your specific device serial number via Garmin Express. Do not manually rename files.

The end.