This board was used exclusively with the SCPH-7000 series of consoles.
I sell MM3 modchips in my store.
PU-20 MM3 modchip installation diagram
Above is the diagram for the PU-20.
The diagram isn't the cleanest so I'd like to clarify a few points that are unclear. Pin six connects to the bottom left most leg of that chip, and pin five connects to the pad to the left of the white line on the board. Pin four connects to the right side of the capacitor, which is the topmost component in that spot.
Here are some tips I have for you when you are soldering your chip into the PU-20.
- 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 where the pin eight circle is seems to be the ideal location.
- Be careful when soldering to pin four, if you apply too much solder, or press too hard, you may knock a component off of the board, or bridge the connection with nearby points.
- When soldering to pin six be careful, you don't want to apply too much solder and bridge nearby pins on the chip.
This section has photos of some successful installations which you can use to get a better understanding of how everything is wired and positioned.
This is an installation I did on an SCPH-7001: