Nintendo´s Controller PAK consists of an SRAM Chip, which is a volatile memory. This means, it is battery-driven. Once the battery has died, all savegames will be lost.
This mod aims to replace this SRAM Chip with a ferroelectric RAM chip (FRAM). The advantage of this Memory is, that it is non-volatile. That means, your savegames will not be battery dependant anymore. The original Tutorial can be found on this site, but here I will go more into detail, describing the mod step-by-step.
Note: This turorial describes the mod for the original Nintendo CPak´s. If you are using 3rd party memory cards, it cannot be guaranteed that this mod will work.
What do we need?
- 3.8mm Gamebit to open the Cotroller Pak
- Soldering equipment (Iron, Solder, Flux)
- De-Soldering equipment (I used: Wick, precision knife)
- FRAM-Chip (FM18W08 or FM28V020)
- Cleaning Equipment (Alcohol, Q-Tip)
- Game that supports Controller Pak (e.g. Perfect Dark)
You do not want to do this mod, realizing in the end that the Controller Pak was damaged. Verify, that the CPak is working and saving is possible.
Step 1a (optional): Back up your files
Using an Everdrive64.
Step 2: Open it up
Unscrew the bolts and you should find the following PCB:
Now, the real fun starts! Heat up your soldering iron, prepare flux and wick.
Step 3a: Desolder the battery
Since FRAM is not battery-driven, we won´t be needing it anymore. Desolder the batt from the PCB. This should be easy. Simply apply flux and wick to the pins and heat it up with the solder iron. I used 400 °C for the large joints. I guess, a bit lower temperatures should be fine as well.
Step 3b: Desolder the SRAM
This will be the tricky part. I will describe the method I used, because i feel confident with it. Beware: Using my method will sacrifice the Chip. If you feel like you could still use the chip, you should go fo a different removal technique.
Basically, you grab a precision knife and start cutting each single leg slow and patiently. Be careful not to slip off with the knife on the PCB. If you cut too hasty, the copper pads could be ripped off and you will end like this:
First, make sure you have cleaned the pins with alcohol. Now, place the chip in a way, that every leg is touching its respective pin. Be careful with the orientation of the IC. PIN 1 is marked with a small cricle on the FRAM correcponding with PIN 1 on the board, which is marked as an arrow. Once in place, you need to have a calm hand. Fix the chip somehow, so it can stay in place. I used to press it down with tweezers, while soldering one side. Afterwards the other one.
Note: Instead of soldering each pin at a time, you should try Drag Soldering, where you can solder an entire row at once. It was also my first time trying this technique, but it worked out well. Here is a demonstration of drag soldering.
Step 5: Functional Test
If everything is soldered correctly, insert your CPak, Game and power up the console. Do not panic if you get the following error message:
In case of any questions, just go ahead an ask