Towards the end of the SCPH-10x PSone production Sony revised the board slightly and released the PM-41 (2) board. This page covers the installation diagram for installing an MM3 chip into the PM-41 (2).
I sell MM3 modchips in my store.
If your board has PM-41 printed on it then you should follow the PM-41 guide instead.
The first time I modded a PM-41 (2) I wasn't able to find an installation diagram, but was able to figure out how everything should be wired through a combination of trial and error, and the diagram for the original PM-41 board.
PM-41 (2) board components and fuse locations
Here are a couple of photos of the PM-41 (2) board. If you click on them they'll open in a much higher resolution format so you can zoom in on the details. This first image shows the front of the board (marked with the letter A).
This second image shows the back of the board (marked with the letter B).
Below is that picture of the front of the board again, but this time it has labels on all of the major board components. This can be useful if you are debugging an issue on the system. For example if your video output is bad you might want to try replacing the capacitors near the video amplifier.
Another common issue people run into is blown fuses. Below is a diagram showing the locations of all of the fuses on the PM-41 (2) board. They are highlighted in yellow, with the fuse value nearby.
PM-41 (2) MM3 modchip installation diagram
Above is the installation diagram. Just match each colored pin label in the diagram with any matching colored point on the board. Click on the image for a higher resolution version. I recommend placing the modchip on top of the CD mechanics processor chip.
I have created additional diagrams primarily for colorblind people. They show one point at a time in a single color (there is a set in red, green, and blue). Because they show the entire board they may reveal more alternative points for each pin. Click on the links below to reveal the sets of images.
I'm creating these new diagrams for each PS1 board revision working from newest revision to oldest revision. It's going to take some time, but should hopefully be more helpful than the older diagrams I had on here before.
Here are some tips I have for you when you are soldering your chip into the PM-41 (2).
- Cut your wires to be as short and direct as possible.
- Don't connect pin two of the chip to anything.
- Pin 3, and 6 can be tricky. Don't push on the components with your soldering iron or they might get knocked off the board. You can use tweezers to carefully solder them back on one side at a time, the orientation doesn't matter.
- Make sure the wire on pin 3 and 6 don't come into contact with both sides of the component (this is especially common if you run the wire directly on top of the component).
This section has photos of some successful installations which you can use to get a better understanding of how everything is wired and positioned.
Here is an example installation have done: