interstat
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Post by interstat on Nov 25, 2017 20:35:53 GMT
Hey guys,
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?
help appreciated!
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Post by zyrobs on Nov 25, 2017 20:49:13 GMT
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interstat
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Joined: November 2017
Posts: 11
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Post by interstat on Nov 26, 2017 20:16:58 GMT
Great - thanks for the reply.
Looks like my problem, will try this out later
Cheers!
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interstat
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Posts: 11
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Post by interstat on May 16, 2018 21:47:10 GMT
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?
thanks guys!
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interstat
Newbie
Joined: November 2017
Posts: 11
Location:
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Post by interstat on May 28, 2018 9:51:31 GMT
After taking my board apart, I'm not sure what revision it it. No mention of "VA", it's marked "171-7069bB and"837-11892-01:PAL" .
I found this thread:
Few people mentioning that the only option for this board is to lift pin 79.
So am I out of luck?
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Post by zyrobs on May 28, 2018 10:33:39 GMT
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? thanks guys!
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.
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interstat
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Joined: November 2017
Posts: 11
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Post by interstat on May 28, 2018 16:50:14 GMT
right click -> save!
thanks zyrobs
Did that and it works fine. My soldering job however is nowhere near as neat as yours. Ended up grounding on the power supply pin...much easier.
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Post by zyrobs on May 28, 2018 19:36:58 GMT
Maybe easier, but you need a thin wire to work with that trace, and it's tidier and safer to not have those hanging through half the board. And no need to glue it down this way either.
Oh, remember you need to connect the thin trace to ground, not the cap end. The cap end is already grounded.
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interstat
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Posts: 11
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Post by interstat on May 29, 2018 19:25:23 GMT
It's not ideal, but I taped down the wire pretty well. I ran it over the top of the board and soldered onto one of the grounds.
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Post by zyrobs on May 29, 2018 19:52:53 GMT
That pic is a 403 error. And you can just solder to the ground pin from the bottom, no need to run the cable through to the top.
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interstat
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Joined: November 2017
Posts: 11
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Post by interstat on May 29, 2018 20:49:30 GMT
duh....can't direct link to the image.
Soldering to the ground pin directly was really, easy.....which is why I did it. I probably need to improve my soldering skills, I seem to be needing to do it more and more lately.
Really didn't want to practice on my Saturn though!
Thanks again for your help.
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