You MUST pair up the set you need with the roms you are currently running. Between the different regions, and versions, different cabinets either had start buttons to start the game, or used the player's action buttons, and no start buttons were installed. After installing these or reverting back to your old version, you must hold the test/reset button in on first boot to clear the memory, or it won't boot properly. Free Play hack v1.0 for TMNT (4P sets) by Pat Daderko (DogP) This is a freeplay hack for the 4 player (2P ROMs are not supported) TMNT arcade game. This hack does freeplay only... there is no DIP or menu selection to enable/disable free/coin play. All known regions in MAME are in this hack, named corresponding to the name of the MAME set. To determine which set you have, look at the numbers on the chips at J15 and K15. The numbers are: tmnt: 963 X21, 963 X22 tmntu: 963 R21, 963 R22 tmntua: 963 J21, 963 J22 tmntj: 963 221, 963 222 tmht: 963 F21, 963 F22 tmhta: 963 S21, 963 S22 tmhtb: (unknown) To use, burn the freeplay ROMs to 27C010 EPROMs and swap with the corresponding chips at locations J17 and K17. If your J15 and K15 ROMs differ than those listed above, you'll need to also burn the J15 and K15 chips from the corresponding MAME set you'd like to use. As always, use at your own risk... this hack has been tested in MAME and on a TMNT PCB, but only briefly.