It isn’t uncommon for video configuration issues to not show the GUI even if the Jetson otherwise booted correctly. More on this below.
Recovery mode is entered if the recovery button is held down while power is turned on or the reset button is hit. Recovery mode in and of itself does nothing to change the Jetson, but it does put it in a mode the driver package on the host can recognize and use to edit the Jetson. To see this on the host you have to use a micro-B to full-sized USB cable. This is what the shipped cable uses. Was this the cable you used? If this is correct you should see a TX2 from:
lsusb -d 0955:7c18
Think of the “recovery” button as a shift key on your keyboard. Recovery mode is the capitilized power on button…hold recovery down and tap the power reset…or if the Jetson is off, hold the recovery down and tap the power on button.
If you have a new board with an old L4T version on it, then flash is recommended even if it all looks good after boot. Regardless, if you have a router and can watch logs to see what addresses are assigned, then seeing an address request means the system booted up ok even if video doesn’t show up. Serial console is by far the best way to see what goes on, but ping of the IP address from a host can be useful as well.
Do you have a router appliance? Can you see an address being assigned, and can you ping it?
In the case of video is this a purely HDMI monitor? Adapters often get in the way and older VGA adapters literally cut the wire used by monitors to report their capabilities to the video card.