After connect to the console port of a new U1910. there are many errors print. details as the snip below.
phy 1 is invalid
phy 0 is invalid
connect FE1 to Lan switch via eth-cable, the error restored.
from the error information, we know that the problem is on LanSwithch, check the network connection we found there is no any network cable is connected to the U1910.