Problem with mac mini 2012 connection

Hello!I have a problem with my mac mini 2012 connection!The hdmi to hdmi connection working great at my mac mini!The thunderbolt(mac mini) to hdmi (display) is not working!But when i have the hdmi to hdmi cable and the thunderbolt to hdmi at the same time (my display have two hdmi output) works fine!!But when i unplug the hdmi to hdmi cable stop working the thunderbolt to hdmi!!Any solution for that??I want only the thunderbolt to hdmi connection!!