Member
- Joined
- Feb 10, 2025
- Messages
- 5
- Reaction score
- 0
- Points
- 1
- Thread Author
- #1
I ran into many stubborn black screen faults with the Sega Saturn, I have a bunch of left over Sega Saturns where recaps, reflows, PSU swaps didn't fix some of my Saturns. They have stubborn black screen faults where every single possible fix I try, doesn't seem to get them working again. And I mostly had success with Modding Sega Saturns. I modded a few dozen successfully. But these few Saturns that I now have, this Black Screen fault, that feels like it's never ending.
And this fault occurred after trying to replace the SMD BIOS, and the SRAM chips, there is excess glue under the bios chip.
Excess heat is required to desolder and unglue the bios chips. And with the mention of PLL chips being unreliable and heat sensitive, and worst of all propeitary and non replaceable. It seems like the PLL's are the culprits for these black screen faults. If they are as unreliable as people say. Why hasn't anyone with the skills, reverse engineered them? The Sega Saturn has gained a lot more interest in the past few years. We essentially have many of the tools needed today to figure out a way replace this PLL chip once and for all, on the earlier revisions of the Saturn. And I wish I had the skills to do it. But i wonder if anyone else has the skills to figure out a way to replace this chip, with a reliable modern replacement.
I would like to know how this chip works, what does it exactly do? And how does it work? Is there something programmed to it? And how does this tiny little Clock Timer chip brick the entire console? From what I can find is that. This is a Sega 315-5746 chip, but what this chip really is. Is it's a Hitachi HD49422 chip. No known replacements for this chip are currently available. And nobody in the modding community either knows about it nor is trying to come up with a replacement. Also this PLL chip, from what I can gather is in the mass majority of the Sega Saturn revisions. All of the Model 1's VA0, VA1, VASD and VASG. All the way up to the early Model 2's, that also have VA-SD and VA-SG Motherboards. But with a very sleight difference, like no battery reset button.
So whatever, it would take to figure out a way to replace these chips, would be great to know about. What kind of steps would have to be taken into account to come with a modern replacement? And what chips can replace this chip, I suspect a flex adapter of some kind would need to be made to solder the replacement PLL to the solder pads of the original PLL.
Schematics for this chip: https://wiki.console5.com/wiki/315-5746
And this fault occurred after trying to replace the SMD BIOS, and the SRAM chips, there is excess glue under the bios chip.
Excess heat is required to desolder and unglue the bios chips. And with the mention of PLL chips being unreliable and heat sensitive, and worst of all propeitary and non replaceable. It seems like the PLL's are the culprits for these black screen faults. If they are as unreliable as people say. Why hasn't anyone with the skills, reverse engineered them? The Sega Saturn has gained a lot more interest in the past few years. We essentially have many of the tools needed today to figure out a way replace this PLL chip once and for all, on the earlier revisions of the Saturn. And I wish I had the skills to do it. But i wonder if anyone else has the skills to figure out a way to replace this chip, with a reliable modern replacement.
I would like to know how this chip works, what does it exactly do? And how does it work? Is there something programmed to it? And how does this tiny little Clock Timer chip brick the entire console? From what I can find is that. This is a Sega 315-5746 chip, but what this chip really is. Is it's a Hitachi HD49422 chip. No known replacements for this chip are currently available. And nobody in the modding community either knows about it nor is trying to come up with a replacement. Also this PLL chip, from what I can gather is in the mass majority of the Sega Saturn revisions. All of the Model 1's VA0, VA1, VASD and VASG. All the way up to the early Model 2's, that also have VA-SD and VA-SG Motherboards. But with a very sleight difference, like no battery reset button.
So whatever, it would take to figure out a way to replace these chips, would be great to know about. What kind of steps would have to be taken into account to come with a modern replacement? And what chips can replace this chip, I suspect a flex adapter of some kind would need to be made to solder the replacement PLL to the solder pads of the original PLL.
Schematics for this chip: https://wiki.console5.com/wiki/315-5746
Last edited: