"It was working fine"....you were playing it and it just stopped?
When you put coins in, where do the coins go and is the .25 cent display the only lamp that is on....or none at all?
Check if there's power coming out of the power supply with a multimeter.
Check the 3 fuses as well...6amp top, 8amp middle, and 6 amp bottom. Use quick blow fuses only.
If you have power, and fuses are good, then check the power supply harness.
Pull up and off the white Molex connector on the motherboard and turn it around.
If it's burned and yellowed on the housing, you can change the female pins, or you can buy a new harness