Dreamcast Outputting Video/Audio Briefly

Recently purchased Dreamcast will output audio/visual briefly 5-10 seconds upon boot up. After that it will not output anything else until the unit is power cycled. Has anyone ever seen this problem before?

Edit: Not sure if it matters but I am using Composite cables and it does the same thing on both TV and XRGB-Mini

 

If it's a VA1 (the later unit with no heatpipes and a plastic fan duct) then a bad fan will do that. Try opening it up and checking that the fan is spinning.