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).
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) MM3 modchip installation diagram
Above is the installation diagram.Since the diagram isn’t the clearest I’d like to mention that third pin connects to the top edge of the right most resistor in that group of three (ignore the bottom end of the white arrow pointing to the middle resistor). Also ignore the empty red circles.
Here are some tips I have for you when you are soldering your chip into the PM-41 (2).
- 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).
- Placing the chip directly on top of the shorter large chip (where it is in the diagram) seems to be the ideal location.
Diagram success rate
Here’s a list of people who have successfully modded their console with this diagram. Leave a comment and I’ll add you to the list.
- William Quade (me) (I’ve used this diagram many times and haven’t had any problems with it)
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 are some sample installations I have done in SCPH-101’s:
This first one has pin one and pin four on the chip connected together. Pin four normally connects to the reset button, but since the slim PS1 doesn’t have a reset button it doesn’t have anywhere to connect. It can either be left disconnected, or connected to pin one (tied to a high voltage signal).