Do not fit an IRF MOSFET where an IRL is specified
IRF-series MOSFETs need a higher gate voltage than a 5 V logic output can guarantee, so they may not switch fully on. Only IRL (logic-level) parts work in these logic-driven positions.
Systems
Source: Repairing DataEast 1987 (Laser War) to Sega 1995 (Batman Forever), Part Two, Clay Harrell (pinrepair.com)