Arcade Legends 1 are run on old PC towers...The CPU is probably toast; that's the problem with those machines, once the CPU goes, it's worthless; not just a PCB that you can fix like with other arcade machines, even AL3 runs on a modified PCB that is coupled with a CPU; but very well built.
The AL1's like the one you took a pic of, literally run on old Dell computers that you could have bought at COMPUSA