The JAMMA TestCard, is a small JAMMA board that lets you test and troubleshoot JAMMA cabinets, or any other cabinet with the addition of a JAMMA cabinet adapter. Simply plug it into your JAMMA harness and you can start testing immediately. The card can be powered from the cabinet power supply or the built-in 3V battery.

The TestCard can display diagnostic information on either the cabinet monitor, or its own backlit dot matrix LCD screen. This means that the tests can be performed in a cabinet with a dead monitor, a dead power supply, or both.

This can come in handy in a number of circumstances, whether you’re building your own cabinet and want to test it long before it's fully functional, or you want to test a cabinet in an unknown state before purchase, and don’t want to risk testing with with and possibly damaging a real arcade game PCB.