Verify navigator serial ports are still working

Hello,

The BlueBoat I’m working on was previously used by an intern, who I believe blew up all of the serial ports on the board (Serial 1, 3, and 4).

Is there an easy way of verifying they are working such as a loopback?
How can I make a ‘putty-like’ session with them?

I have tried connecting a very simple GPS, set appropriate parameters, and still nothing on all ports. As well as trying several other instruments.

Cheers