As you have mentioned that there is no Green Dots on the clients, that means there is no communication between the SEPM and the SEP clients. Obviously Clients won't update their definitions from the SEPM. That means if you fix the Communication issue. This will be fixed.
On the SEP client, under help and support, and Troubleshooting, does it say server offline?
If Yes, please try the following Link to test communication-
http://service1.symantec.com/SUPPORT/ent-security.nsf/docid/2007101711140148