This was one of the earlier PlayStation 1 board designs that included RCA composite video output ports on the back. Most SCPH-1001's here in the United States had this board inside.
I sell MM3 modchips in my store.
Additionally many Japanese systems had this board including many SCPH-3000, SCPH-3500, and SCPH-5000's.
PU-8 MM3 modchip installation diagram
Above is the diagram for the newer version of the PU-8 board. It has the smaller CD mechanics controller chip right next to pin 3.
All of the points being soldered to are pretty straightforward pads. They are all located on the bottom side of the board. You can ignore the other chip on the board. Some early PS1's had a chip soldered like that onto the board from the factory.
Below is the diagram for the older version of the PU-8 board. It has the larger CD mechanics controller chip right next to pin 4.
Here are some tips I have for you when you are soldering your chip into the PU-8.
- Cut your wires to be as short and direct as possible.
- Don't connect pin two of the chip to anything.
- Pin 4 can either be connected to the pin 4 location in the diagram, or pulled high by connecting it to pin 1 on the chip.
- Placing the chip towards the middle of all of the pads you need to solder to is ideal. If you flatten the legs on the chip it will fit underneath the board without any modifications.
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-1001's:
This image shows a cleaner way to install the chip with six wires. I probed the board with a multimeter to find alternate points to solder the wires to that are much closer together. The only real tricky point is soldering pin six to the leg of the surface mount chip.