Blades not coming back online

We recently moved our equipment to a new data center. We have have some older compute nodes, they are all PowerEdge M600 in PowerEdge M100e enclosures. These are all powered up but for some reason they cannot be seen on the network.

If I log into the Dell Chassis Management Controller interface for the enclosure I can access them. I have tried setting the First Boot Device to PXE and warm booting them boot they still did not come back. I really don't know much about this equipment and would greatly appreciate any advice that would help me trouble shoot this and get them back on line.

thanks