I picked up a dead Raiden Fighters a while back and I'm working my way through it. Right now it gets power but aside from some occasional interference on the screen, it doesn't do anything. A couple odd things I noticed, the cart was decased and it had some official looking label that is Korean maybe? Also the CPU on the mobo is clocked at 40mhz whereas all the documentation I can find says it should be 25mhz. The single PCB boards are supposed to be 40mhz, but this is not that. The oscillator next to the CPU is 50Mhz so it seems this 40mhz processor is getting run at 25mhz. I can't see any signs that the processor was replaced, but I have no idea why it's set up like this. Flexing the board doesn't change anything and I don't see any obvious signs of damage on the board. It has all the custom Seibu chips along with the Yamaha sound so it doesn't look bootlegged nor like the single board setups.