polymorph:
Many years ago, I was manager of a video arcade. When the power supplies failed, we replaced them with generic switch mode power supplies.However, I found out that without grounding, just the leakage from parasitic capacitance in the power supply was enough so that the chassis would float at 1/2 of the line voltage, 60V here, and with enough current to give you a palpable shock. I discovered this by touching the chassis of two games, one with a broken ground lug on the cord, the other properly grounded.
Did you ground the metal enclosure of the arcade game and power supply box or the low voltage side of the power supply?
All metal enclosures shouldn't have been grounded according to local regulations anyway?