http://antelopearcade.com/forum/yaf_postst4_Pinball-2000-AT-to-ATX-Power-Supply-Replacement.aspx
Also ...... The PC inside a Pinball 2000 game always runs at 120v AC as it gets it's power from the transformer in the pinball cabinet. So if you are in a country that uses 240v DO NOT plug in the PSU directly to the mains socket with a PC mains lead. If you need to run the computer out of the game to do diagnostics on the motherboard, check that the switch on the back of the PSU is at 240v before plugging in into the mains! Also remember to set any PSU back to 120v before installing it in the game and powering up the pinball machine.