Response from Jonathan: Massimo,

When we get a message that says “no signal” on an arcade monitor, it usually means that the monitor is not getting a video signal from the main game board. It’s possible that it could be an issue with the monitor itself but this is pretty rare in our experience. We recommend checking the connection between the game board and the monitor to make sure it is good. You may think about replacing this cable entirely to see if it’s causing the issue. If the connection is good between the monitor and the game board, then you are probably experiencing a problem with your main board. At this point, you might try replacing the video card entirely to see if it solves the issue. Since this game is fairly new, you might try contacting the distributor you bought it from the see if they can help you out. You could also try contacting Sega amusements directly at segaarcade.com to see if they have some thoughts on your issue.

Hope that helps. Thank you for your question and good luck with your repair.