You can use Xterm as an alternative terminal to figure out why gnome terminal is broken. The likely scenario is that the /etc/default/locale file got messed up during the ROS install.
From within Xterm, if you attempt to run gnome-terminal and get status 8 back, that’s the culprit. Older versions of the ROS instructions setup the locale, which Ubuntu 16.04 apparently takes exception to. If you can get the locale correct again, everything should work correctly. Since you have another TX1, you can probably just copy the locale settings from there. Make sure to reboot the machine after copying for the change to take effect.
Instructions for cloning are available on the Jetson TX1 Wiki:
http://elinux.org/Jetson/TX1_Cloning
As I recall, there are three different terminal programs on the TX1, Terminal, Xterm and UXTerm. If you can get one of those to work, you should be able to get the IP address using ifconfig.