We have problem an 1260 Agilent HPLC. We can't see the modules. This problem start with a detector G1314F FW B.07.01. The LACE driver is A.02.03
Assuming that 1) this is not a serial connection situation and 2) nothing has changed and none of the modules has red-lighted, I would go through all of the CAN and Ethernet cable connections, removing and reseating the cables a few times each to make sure connections are good.
Then I'd power cycle any ethernet switches between the Agilent stack and the LAC/E. Absent any improvement, I'd power it all off (Agilent stack and LAC/E), then turn on the LAC/E, let it fully boot up, then turn on the Agilent stack starting with whatever the Lan cable going toward the LAC/E is plugged into.
If that fails, log onto the LAC/E and try pinging everything listed in the DHCP window under node properties as well as via the Agilent configuration app that should be on the LAC/E desktop. This should help you identify the problem...