Response from Jonathan: Marco,

It sounds like someone has swapped the wires for the different colors either on the monitor input connector or somewhere else on the monitor chassis. Of course, this could also be related to some bad parts as well. We recommend double checking the wires that run from the board to the monitor chassis to make sure they are hooked up correctly. You may need to consult the harness pinouts (which can usually be found in the manual for your game) in order to accomplish this. You can also try Installing A Cap Kit as there may be some color issues associated with bad caps as well.

On the coin mech, you can typically adjust a coin mech fairly easily by adjusting the screw on it to take a larger or smaller size. Check out our post on Adjusting A Coin Mech for more information. Keep in mind that you may need to replace the coin mech entirely if you cannot get it to take the coins that you want it to take.

Hope that helps. Thank you for your questions and good luck with your repairs.