Hello.
I recently installed a RouterBoard 600a with 8 Ubiquiti XR2 and Daughter board. It worked fined for awhile but, lately it had locked up. I power cycle, did a hard reset, and can’t communicate with the router through neither LAN ports. Had anybody had the same problem?
Please help.
Thanks in advanced for your help. 
yes with 4xx Series… eth lock up. try to enter by wireless and disable/enable eth ports..
regards giuseppe
Thanks for replying.
Already did it but, it didn’t work.
I’m trying to connect to the router via serial port but, don’t know how to do it. Any other idea?
try to disable speed autonegotiaton
You could have had a surge on the data lines taking out the coils in the ethernet connectors.
The weird thing is that. There hasn’t been any storm, or anything lightning. I even have a surge protector that protects all the equipment in the lan.
from the serial console does the ether port display as registered when pluged into a switch, router or device?
If so then it is possible I am not correct.
I am only giving a possible scenario, you must continue your diagnostics and verify waranty etc.
When I plug a cable into the LAN port, the light comes up but, no communication.