All its there for is to keep the FCC off Sega's back by suppressing some of the noise that could be radiated via the power cord so it meets the limits of a FCC Class B digital device. Replacing it with a footprint-compatible part not specified as an exact equivalent, may give you a warm and fuzzy feeling, but does nothing for the FCC without emissions testing. However, if the replacement part has an adequate current rating, is intended for a similar application, you already have it, and the board is in good enough condition to withstand the rework, you might as well fit it, as it *MAY* help with EMC.