isaberg
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Post by isaberg on Dec 6, 2012 21:14:25 GMT
I have a VA1 with the SW4 connector in the battery compartment. Can I just connect the two middle points and call it a day, or does it need more work? I think I've read somewhere that it's not as easy on the model 1 boards as the early model 2 ones, but I can't find any information now.
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Post by zyrobs on Dec 8, 2012 15:40:57 GMT
VA1 PAL boards have a small snafu in their design, in that the VDP2 pin 79 and PLL pin 1 are still connected. You can use the SW4 method, but you will also need to raise the pin 1 of the PLL and ground it separately. In practice however, that pin pulls itself low, so you can just cut the trace leading to it (which is a little difficult as there is a capacitor right on top of it).
The PLL is IC20 on the board, it's the little oddball chip labeled as 315-5746. The trace you have to cut is also partially obscured by a white triangle marking between the cap and the IC. Be careful to not accidentally cut the trace leading to pin 2 though!
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isaberg
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Posts: 5
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Post by isaberg on Dec 15, 2012 19:48:20 GMT
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Post by zyrobs on Dec 15, 2012 20:35:39 GMT
That is the line that leads to pin 1 of the PLL, but the last two times I tried cutting it, the machine refused to boot, only after the 2nd attempt at doing so. I imagine there is either something else connected to that line that I can't see, or the capacitor it runs under simply interferes with it some way. Lifting the pin worked 100% though.
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isaberg
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Joined: December 2012
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Post by isaberg on Dec 25, 2012 7:08:46 GMT
In the end I lifted the pin. It worked out great. Thank you very much  |
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Post by tn0w on Jan 30, 2013 22:30:33 GMT
i want to do the mod as well and have a va1 board. Is it also possible to lift pin 79 from the graphics chip as described in this tutorial? www.mmmonkey.co.uk/sega-saturn-5060hz-mod/Or is there no other way then to cut the pin1 line leading to the pll. Dont want to mess up my saturn  |
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Post by zyrobs on Jan 30, 2013 22:54:02 GMT
Lifting pin79 on the VDP2 works on all models, but it is the most difficult method (the pin is very small), and if you end up cutting that pin, you are screwed.
Try cutting the trace in the image above, and if it doesn't work, raise pin1 of IC20.
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Post by tn0w on Feb 2, 2013 16:33:37 GMT
I was willing to take the risk and decided to lift pin 79 on VDP2 and wired it to the switch.
then wired ground and 5v to the psu and...
... My saturn is now capabable of 50/60hz!! ;D
Thanx for the info.
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