So I have been digging around and found my old SNES and games. So I wanted to replace the batteries in my games but if possible I wanted to see if there was a way I could keep my save. My first go with Super Metroid did not work but my next 2 attempts with Donkey Kong Country and Legend of Zelda both worked without any issues.
Some shots of the Super Metroid PCB
And check and make sure the game is still saving
For my first attempt I decided to try powering the SRAM directly, to do this I cut off the end of a mini USB cable and stripped the red (+5v) and black (ground) wires.
Then I checked the data sheet and wired the USB cable onto the chip to give it a 5v supply
http://pdf1.alldatasheet.com/datasheet-pdf/view/108057/LG/GM76C88AL-15.html
And installed the new battery
unfortunately the save was lost but I still have a few more ideas. Next up I tried Donkey Kong Country but no pictures of that so instead here are some pics from Legend of Zelda. First gotta check and make sure the game still has a save.
OK next take lets take it apart.
Next using the same USB cable from Super Metroid this time I soldered so that the whole board has power. I soldered to the capacitor right by the 5 volt pin.
Now that the board has power from the USB cable I can remove the battery
Then install a new battery
Then disconnect the USB cable from the PCB
Now plug it back into the SNES and my save is still on the cart
A few things to consider temperature increase the resistance so let the board cool down after soldering the USB cable onto the board before you remove the battery.and let the battery cool down before removing the USB cable.
Some shots of the Super Metroid PCB
And check and make sure the game is still saving
For my first attempt I decided to try powering the SRAM directly, to do this I cut off the end of a mini USB cable and stripped the red (+5v) and black (ground) wires.
Then I checked the data sheet and wired the USB cable onto the chip to give it a 5v supply
http://pdf1.alldatasheet.com/datasheet-pdf/view/108057/LG/GM76C88AL-15.html
And installed the new battery
unfortunately the save was lost but I still have a few more ideas. Next up I tried Donkey Kong Country but no pictures of that so instead here are some pics from Legend of Zelda. First gotta check and make sure the game still has a save.
OK next take lets take it apart.
Next using the same USB cable from Super Metroid this time I soldered so that the whole board has power. I soldered to the capacitor right by the 5 volt pin.
Now that the board has power from the USB cable I can remove the battery
Then install a new battery
Then disconnect the USB cable from the PCB
Now plug it back into the SNES and my save is still on the cart
A few things to consider temperature increase the resistance so let the board cool down after soldering the USB cable onto the board before you remove the battery.and let the battery cool down before removing the USB cable.