When I turn on the Dreamcast it comes on for 10-15 secs then dies.

When turn on my Dreamcast the boot up screen comes on and loads up but after 10 - 15 secs the screen goes black and I can’t do anything. No more noises if I move the controller or anything. I thought it was the controller board since I replaced the battery on it but if I unplug the controller port from the system and boot it up I get the same issue.