I've previously modded a PAL model 1 Saturn for 50/60Hz by wiring a switch into the middle 2 points of the row of 4 at the back of the Saturn, next to the battery. labeled "SW4".
I tried this on a new model 1 Saturn that I recently acquired, and it doesn't seem to have worked. When I flick the switch, and short the points, I get an undisplayable signal on my tv. (My OSSC measures the refresh rate of this signal at 75Hz).
I understood that all PAL model 1 Saturns could be modified using this technique. Am I wrong?
Is it worth pulling the main board out, and wiring a switch across JP1 and JP2? Or does it sound like something else may be wrong?
Being a very lazy person, I've only just got around to doing this fix!
however, the very useful image url kindly posted by zyrobs has expired! Does anyone have a copy of it? Or can someone post a new one?
Looks like you picked the wrong day to quit sniffing glue!
Here's the pic.
You can see the trace cut, and there's a small 28AWG kynar wire connecting the trace to the ground plane on that capacitor side. That trace connects to the PLL, which needs to be grounded separately. Once you do that, you can use the JP1/2 jumpers for the 50/60hz mod without lifting any pins.
This is necessary for VA1 PAL boards, which have a design snafu in that the PLL is still connected to the JP1/2 jumpers. On other model 1 PAL units, they are separated.