To reproduce the fault, I ran the Saturn for more than an hour until it was thoroughly warmed up. The music player was more than sufficient for this. I then made some recordings to help narrow down where the noise seemed to be coming from.

This meant investigating the Saturn’s internal power supply, which contains mains-voltage circuitry. Sega’s own documentation warns against opening the console because of the electric-shock hazard. Working around an exposed PSU while it is connected to mains is not something to attempt unless you are appropriately qualified.

From what I could hear, I suspected either one of the transistors, the bridge-rectifier circuitry or the transformer. But I was guessing. I am absolutely in no way trained in electronics.

What I could establish was that compatible power supplies from two Model 2 Saturns I owned did not produce the same problem. That does not mean every Model 2 PSU can be swapped into every Model 1, since Saturn PSU compatibility depends on the motherboard revision and PSU type.

I’d buy another power supply separately if I could track one down, but these things are becoming harder to find. This problem is also giving me a good reason to investigate whether I can replace the original PSU with an external DC-powered arrangement instead.

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