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Sega Saturn VA13 recap, 50/60 switchless, new FRAM

Posted: Wed Sep 30, 2020 2:51 pm
by Steve
I've been doing some work on my VA13 Saturn model 2.

At first I just wanted to do a re-cap and FRAM mod, but after opening the machine up and seeing the quality of the pre-existing 50/60 switchless mod I decided to clean that up too. Replacing the SRAM with a new FRAM chip in the Saturn allows the game saves to be kept for up to 150 years according to the data sheet, where as with the original SRAM the saves would be lost when the CR2032 battery dies or gets replaced.

* Recap mainboard & PSU
* Clean up 50/60 switchless mod
* Replace FRAM

This mod was already on my Saturn when I bought it, it is the 50/60hz switchless mod. I wasn't happy with the quality of the install, needlessly long wires, super-large resistors lol etc. Just not very elegant!
originalmod.jpg
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This is how it looked after cleaning the mod up.
fixedmod.jpg
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I re-capped the mainboard - I didn't have stock of the extra small types of capacitors needed to fit under the metal shielding, so I laid them down. Not pretty but it does the job, the caps are all top-spec.
recapped.jpg
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Here is the original epson SRAM. I covered the surrounding components with kapton tape which will insulate the heat from my hot air station.
epsonchip.jpg
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Really clean removal using my hot air station on 377 degrees 50% air.
epsongone.jpg
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New f-ram installed and pins 28 & 22 lifted.
newfram.jpg
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Connected pin 28 to vcc and pin 22 to ground.
framwired.jpg
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Notes:
Good website for FRAM installation instructions on various models of Saturn:
https://www.consolesunleashed.com/guide ... all-guide/
Link to the FM1808B-SG chip on mouser.co.uk:
https://www.mouser.co.uk/ProductDetail/ ... vLwQ%3D%3D

Re: Sega Saturn VA13 recap, 50/60 switchless, new FRAM

Posted: Wed Sep 30, 2020 8:54 pm
by Steve
I also decided I didn't like how the bios chip had been soldered. Previous owner broke some pads and patched one underneath the chip making it sit crooked. This is my machine so I kind of want it perfect, so I removed the chip, cleaned it up, redone the trace patches but this time patching to the via on the rear. I know, it makes no electrical difference but I'm just more confident knowing I did it.

Before: wonky, bad angle, mangled legs, not good patching.
PXL_20200930_183021355.jpg
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Removed, you can see the patch trace from underneath now.
PXL_20200930_184822114.jpg
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Patch the trace from the rear this time.
PXL_20200930_193503350.jpg
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Voila. Beautiful. :)
PXL_20200930_194317249.jpg
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