Ultracade game won't boot up

Working on an Ultracade and when I turn the game on it makes a single tone (sounds like the sound a Mortal Kombat 4 makes when you first power it up and it is going through all the checks) then repeats the same sound every 45 seconds or so. It will not come up on the monitor (just a white screen) nor can you hear it play blind. I hear the computer running and the cooling fans are running. I have checked and made sure all cable connections are secure. Anything else I can check?

Thanks