Marco V

Hello everybody, I had the unique change to buy 2 Space Invaders cocktail tables. At first both doesn't work, one was fallen and had no window. The second is almost working! The screen is working, i hear a sound when i put the power on so almost gaming. But the problem i have is that it is a machine for coins. And that part doesn't work well. The counter of the machine is working when i 'click' the black part but the machine is still saying that i have no credits. I have really no idea what this could be and how to solve it. Is there anybody ho knows to free play or to fix the coin counter? Thanks a lot and i attached some pictures so you can see my beautiful machine