Check out the files in the BOOT Partition - it looks like the system is not booting properly. If it is, then you should see the Ethernet getting an address via DHCP (look in the router tables) and then be able to ping the Parallella.
viewtopic.php?f=50&t=1162
If the three files in the BOOT partition are incorrect or missing the baord will not boot
viewtopic.php?f=23&t=1236#p9115