micro usb port on TX1 board can not work

I connected the USB micro port on TX1 board to my host PC.But no nvidia device can be found.All of my 3 boards have this problem.When connected to usb host,the voltegle of D+/D- is low level,which is abnormal and is the reason for this issue.

Host will only see a device if the Jetson is in recovery mode and the cable is the micro-B type (which is what the provided cable is). Without recovery mode the port functions as an ordinary host connector…you could plug in a keyboard/mouse here, and it would work on the Jetson.

Recovery mode implies holding down the recovery button while bringing up power or resetting power. Assuming the right cable is used, and that the Jetson was brought up in recovery mode, the PC host will see output from this for a TX1:

lsusb -d 0955:7721

Are you sure the Jetsons are in recovery mode? If there is still a failure after meeting those requirements RMA would be required.

Yes,you are perfectly right.