PU-18 MM3 modchip installation diagram

This board was used with a wide range of consoles from the SCPH-5000’s, and SCPH-5500’s, to even some SCPH-7000’s and SCPH-7500’s.

For more information about MM3 chips click here, for more information about PS1 modchips click here.

PU-18 MM3 modchip installation diagram

MM3 chip pinout

PU-18 MM3 modchip installation diagram

Above is the diagram for the PU-18. Only seven wires are needed for this board, just leave pin two disconnected.

All of the points are fairly easy to solder to, with the only tricky point being pin one. Just don’t apply too much pressure or you might knock the capacitor off of the board.

Installation tips

Here are some tips I have for you when you are soldering your chip into the PU-18.

  • You don’t need to connect pins four and two.
  • Placing the chip in between the circles for pins 3, 5, and 6 seems to be the ideal location.
  • Flatten the legs of the chip so it can more easily fit underneath the board.

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.

  1. William Quade (me)

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 in some SCPH-5501’s. The first image shows a somewhat cleaner installation using alternate points for pins 1, 3, and 8. Chances are there are alternate points for 1 and 8 that are on the chip I soldered pin 3 to, which could result in an even cleaner installation.

MM3 PU-18 install

The image below shows a more standard installation using all of the points in the diagram.

PU-18 MM3 installation

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Ric I.
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Ric I.

Completed my SCPH-5501 and now booting backups – what an adventure!!! Thanks to Williams for this page.

Nathan Face
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Nathan Face

So I don’t need to use pin 4?

Hull Kogan
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Hull Kogan

Thanks for the clear tutorial. I was able to get it to work with my 5501.

Kenneth Ahearn
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Kenneth Ahearn

everywhere i look i see this 1st point labeled somewhere else with this contact point used as an alt. is there a reason your first contact point uses the alt point?

Eric
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Eric

I really appreciate you hosting these instructions. It worked awesome for me!!

Fabio Gutierrez Hernandez
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Fabio Gutierrez Hernandez

Its full works thank you

heavenchai
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heavenchai
BABER
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BABER

HY DEAR ALL

Terry H
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Terry H

Hi, I just cracked open the case of my SCPH-5502 with the intent of installing an mm3 chip, only to discover it already has a chip of some description already installed, with two of the points (5 & 6) being occupied. There’s 6 wires on the chip but one (red) is disconnected and I’m not sure whether it was like this before I opened it up or whether I’ve inadvertently knocked it off somewhere along the way. A little help regarding what this chip’s function is and where to proceed from here would be greatly appreciated, thanks. https://imgtc.com/a/PBvWvqH

Nick stovall
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Nick stovall

Thanks for the install guide bought some chips off you a long time ago I was able to install it in the matter of about 10 minutes and it fired my backups right up

Ozark
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Ozark

Thanks for the guide! I just installed a PIC12F675, using a recompiled version of the PIC12F629 code (https://assemblergames.com/threads/ps1-mm3-for-12f683-12f675.53679/#post-873536).

You say that pin 4 is not required, however to get it working I had to link that one in. After checking the source code of the firmware, pin 4 is indeed used in multiple parts of the code.

With a tweak to the laser intensity, and Verbatim DataLifePlus media, it’s working flawlessly. It’s like 1997 again!

travis
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travis

i did my installation it worked, then after putting the case back on, im stuck on the white sony screen. took chip out still does the same, everything else that looks fine on the board, any ideas?

Justin Weber
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Justin Weber

Hi William, Thank you so much for this informative website, everything is extremely well done. With that being said I am having some difficulty with my first mod with the PU-18 using the first circuit diagram provided with all seven wires used including pin 4. What I’m seeing is that the white background boots up with the backup disc and then moves to the Memory card/CD player screen and normal discs continue to operate fine. I’m happy with the solder joints but I’m questioning whether I used the correct chip. I purchased the PIC12C508A-04/P directly from Microchip and loaded the… Read more »