AS-2518-54 Rev A Rectifier Board. Fully Tested and showing all voltage readings.
Games: Gold Ball and Grand Slam. (although the Transformer can be used on all previous games as long as you know how to wire it correctly to each rectifier board).
These Transformers are now RARE. It is important you (or preferably a qualified pinball / electronics technician) checks and ensures your machine is working before installing this board.