EST-2 CPU Fault

When power on EST-2, piezo immediately sounds along with a serious of relays clicking. After a few seconds, top relay near SIGA/B on 2-MCM continues clicking every 0.5sec. CPU fail LED illuminates. Any ideas?

Power down the panel.
Reseat all the ribbons and power it back up.

Hope that helps with out going in to more troubleshooting.