CUAV V5+ over voltage

I accidentally gave cuav v5+ 12 volt over serial port. Now device is booting I hear the booting tune and also I can connect device with cuavlink telemetry but I am not able to connect it with serial port. does anyone have any solution?

Sounds like you broke the hardware I’m afraid. You can of course open it up and inspect the parts and figure out what is broken and fix it but that’ll take some time and skills.

Or alternatively just use other serial ports.