What was your upgrade scenario - in place, Linux/Windows, remote/embedded DB?
Silent or Gui upgrade? Silent or Gui configuration wizard?
Did you first run the configuration wizard on the gateway before attempting to start the DPS?
The first time the DPS starts it can take several hours to complete the upgrade tasks in part depending on what database maintenance was done prior to the upgrade itself, disk and network performance, number of CI's etc.
Have you checked these logs on the DPS for activity?
tail -F <TOPAZ_Home>/ucmdb/runtime/log/cmdb.dal.log
You can also monitor the below log files:
Hope that Helps!