PM-41 (2) Mayumi v4 modchip installation diagram

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 a Mayumi v4 chip into the PM-41 (2).

I sell Mayumi v4 modchips in my store.

If your board has PM-41 printed on it then you should follow the PM-41 guide instead.

For more information about Mayumi v4 chips click here, for more information about PS1 modchips click here.

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).

PM-41 (2) board front

This second image shows the back of the board (marked with the letter B).

PM-41 (2) board back

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.

PM-41 (2) major components

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) fuse locations

PM-41 (2) Mayumi v4 modchip installation diagram

PM-41 (2) Mayumi v4 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.

View individual points in red
View individual points in green
View individual points in blue

Installation tips

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.
  • The high speed clock line (pin 2) needs to be especially short and carefully routed.
  • 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).
  • Don't apply too much solder to pin 2 and pin 4 or you'll bridge the pins on the chip.

Example installations

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 installations I've done on some SCPH-101's:

PM-41 (2) Mayumi v4 install


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March 7, 2019 2:21 PM


Did You notice "chirping" noise? Like this?

March 8, 2019 3:46 AM
Reply to  William Quade

It shouldn't, but this motherboard (PAL) with ONEchip installed actually chirps, so I'll try to figure out if other modchips works different/better. I thought about using two modchips at once.

March 8, 2019 8:41 AM
Reply to  William Quade

Check this thread

More or less that's why I am asking about Mayumi.

October 5, 2019 4:34 AM
Reply to  William Quade

Okay, to clarify (after long time, lol) You didn't have any chirping on either MM3 or Mayumi on PM41(2) board?

BTW, good people here found out, that point 5 on this board is actually wrong (RFCK instead of WFCK).

December 7, 2020 1:26 AM

Hi William

12f629 programme mm3 will it work on pu-41?

Last edited 1 year ago by Robert