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.

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.

  • 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 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.

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.

PU-18 MM3 example 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

103 Comments
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Ric I.
Ric I.
February 25, 2018 9:12 PM

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

mopspear
September 12, 2021 10:26 AM

It was pretty easy. It works perfectly fine. I’m brand new to soldering.

Nathan Face
Nathan Face
April 27, 2018 4:24 PM

So I don’t need to use pin 4?

Nathan Face
Nathan Face
April 28, 2018 10:33 AM
Reply to  William Quade

There’s something giving me problems with this board. The PS works without the chip but when I install the chip it won’t read disc. I’m having the problem with 3 different boards, any ideas?

Nathan Face
Nathan Face
April 28, 2018 6:22 PM
Reply to  William Quade

I had a couple bad MM3 chips. I got them working now!

Jose medina
Jose medina
January 15, 2019 6:30 AM
Reply to  Nathan Face

I’m having the same issue

Hull Kogan
Hull Kogan
April 27, 2018 6:26 PM

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

Kenneth Ahearn
Kenneth Ahearn
May 16, 2018 2:50 PM

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
Eric
May 18, 2018 4:54 PM

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

Fabio Gutierrez Hernandez
Fabio Gutierrez Hernandez
May 31, 2018 9:15 PM

Its full works thank you

heavenchai
heavenchai
June 15, 2018 4:57 AM

Another successful install! Thanks! https://twitter.com/heavenchai/status/1007559837570330624

BABER
BABER
July 15, 2018 7:30 PM

HY DEAR ALL

Terry H
Terry H
July 22, 2018 10:13 PM

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

Terry H
Terry H
July 23, 2018 12:30 AM
Reply to  William Quade

Excuse my ignorance man, I’m fairly new to this sort of thing so I’m not really sure how I’d even find out where the wire came from using a multi meter. I could definitely have a go if you could tell me what to look for.
If you reckon it should be okay to just remove the existing chip without killing the board I’ll just go down that route and carry on with the MM3 as per the diagrams.
Cheers.

Terry H
Terry H
July 23, 2018 12:53 AM
Reply to  William Quade

Upon closer inspection it looks as though that red wire came from here (see pic). comment image

Terry H
Terry H
July 25, 2018 9:13 PM
Reply to  William Quade

Hey man, I got around to installing my MM3 chip, turned on the console only to discover the picture is in black and white and very grainy which leads me to believe the chip that was already installed was some sort of patch to do with the video. The fact that the chip was on a board kind of makes it feel like it may have been a factory mod all along. what are your thoughts, is this fixable? Thanks.

Terry H
Terry H
July 26, 2018 6:23 PM
Reply to  William Quade

Sorry my bad, the first three TV’s I tried were all NTSC and varied from b/w to only blue+green to no picture at all, and then I tried on our old tube PAL tv and it works fine, so there you go. Can’t get Burnt ROMS to boot though, so not sure if modchip issue or disc burning problem.

The original Dave
The original Dave
September 11, 2018 1:50 PM
Reply to  Terry H

Hi Terry! Could be the disc burning or the CD-R‘s used… Haven‘t been using backups since back in the late 90‘s to early 2000, but I remember my PS1 (SCPH-5552) being very picky about that. The thing absolutely hated cheap CD-R‘s and even the ones of good quality needed to be written on low speeds (4x max). Otherwise the PS1 would fail to boot the game and go directly to the menu after the boot animation, as if no disc was present at all. High quality CD-R‘s were kinda expensive then, like aprox. 10 EUR per disc in todays money.… Read more »

Nick stovall
Nick stovall
October 20, 2018 3:33 AM

I buy the cheap cd-rs and yea that is a problome if I burn them with my Windows computer they always seem laggy and only work for a little while and that’s burning on any speed I tried slower speeds and I tried faster speeds didn’t make a difference then I use the same exact disc burner plugged it into my MacBook the slowest speed it will burn is 10x but they work perfectly so I’m not sure what that’s about 😂

Alessio S
Alessio S
July 12, 2020 4:55 AM
Reply to  William Quade

I am having the same problem. Only the PAL games show in color whereas the NTSC games show in black/white.

Nick stovall
Nick stovall
October 20, 2018 3:34 AM

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
Ozark
October 23, 2018 5:46 AM

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
travis
October 23, 2018 4:17 PM

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?

travis
travis
October 23, 2018 7:22 PM
Reply to  William Quade

i did, thank you for the reply my man. sorry to bother you honestly haha. but yeah everything is correctly in. and no solder around or “splash” on anything. if i killed the ps1 its my fault lol at least a new one is 15 bucks and ill at least have the chip.

travis
travis
October 23, 2018 7:24 PM
Reply to  travis

also one first start up with the case on, the screen kinda had a slight flicker, but i moved the tv cable and it went away, after it stay at the white screen i did notice a smell. either plastic or something else, but i looked at literally every single piece , nothing is bloated or blackened

Justin Weber
Justin Weber
October 25, 2018 8:17 AM

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 »

Justin Weber
Justin Weber
October 25, 2018 10:48 AM
Reply to  William Quade

Minipro Version 6.60, software came with my Minipro programmer that I typically use for PROM chips and it works well, first time programming a PIC but the software seems to support it as it has the option for the 12C508A. I also have a MPLAB ICD 4 but I haven’t used it yet.
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Justin Weber
Justin Weber
October 25, 2018 11:42 AM
Reply to  Justin Weber

I’m not familiar with the fuse or calibration values should these have been provided by microchip as delivered? If so, maybe that is my problem and I overwrote them…Looking back at the program window it looks like two checkboxes are present for con.Fuse Bit and USER ID, I’m guessing if those are checked and your hex code doesn’t have values for them they get blanked “OFFF”? If so, could I just correct that and reprogram the chips?
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Justin Weber
Justin Weber
October 25, 2018 12:24 PM
Reply to  William Quade

This isn’t the one installed but I did all ten chips the same, there doesn’t appear to be anything there.
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Justin Weber
Justin Weber
October 25, 2018 7:42 PM
Reply to  William Quade

I could probably make the wires a little shorter but they look fairly comparable to your lengths…maybe I messed up and lost track of pin one with the heat shrink…I’ll cut it open and take a look at that too. Just bought one of your programmed chips as well to try out.
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Update: Pins seem to be in the correct sequence after checking with the heat shrink removed.
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Richard Bradbury
Richard Bradbury
March 29, 2019 2:45 PM

I did mine just like the instructions say and used one of the pictures for comparison…now my discs won’t spin. ..

dani
dani
June 24, 2019 2:58 PM

I bought the MM3 for ntsc-j. I installed it and everything seems ok, but the psx only read j-games (I have a psx NTSC-J), I put parasite eve II (usa) and it didnt load.

Matt
Matt
June 27, 2019 1:03 PM

Hello, I may need help. My ps1 is a 5501 but my board doesn’t look anything like this one or any of the other boards for the other models. It does say PU-18 on it but they don’t look the same. I can only see half of the board though so it’s possible that it may be the other half. But there is a piece of metal covering soldered to the board covering half of it. Is this the part I need to be looking at for the chip install?

Jon
Jon
July 21, 2019 10:18 PM

Worked like a charm on my scph-5501. First try it seemed to have an issue, but I had a soldering issue. After I fixed my mistake, all was good. Thank you!

Michael
Michael
August 30, 2019 12:51 AM

Don’t have any backups to try yet, I don’t have any blanks CD’s until tomorrow, but I tossed in a regular game, and it played just fine, however I have zero sound now. Which pin or connection would it be that could cause no sound if it were shorted?

Radek Michna
Radek Michna
October 11, 2019 6:58 AM

Hello can you send me only MM3 for my PS1 SCPH 5502? I Have EUR console. I need play games in PAL and NTSC its a possible?
Thanks..

RSX
RSX
October 14, 2019 5:51 PM

Works but it doesn’t boot libcrypt, use the alternate #1 point then test with dino crisis:comment image

RSX
RSX
October 15, 2019 9:01 AM
Reply to  William Quade

Not supposed to but I wired it with both diagrams and this one worked, the other crashed with the anti-mod screen. Only changed one wire, everything else was left alone.

Donald
Donald
March 28, 2021 12:17 AM
Reply to  RSX

I had this same issue, Spyro 3 crashed with the AntiMod screen with the original Vcc point, and works with the alternate point.

max
max
April 8, 2020 6:59 AM
Reply to  RSX

No current modchip can bypass LibCrypt-protection.
You have to either patch the disc-image or burn a properly created disc-image with subchannel data (ccd and similar formats) in a special way, which not all burners may support.

NOTE: LibCrypt is not the same as Anti-mod.
LibCrypt = PAL-only = checks, if the disc is original by comparing the console’s response to intentionally broken subchannel-data on the disc.
Anti-mod = NTSC-only = checks, if the console has been modified with an (old) modchip

Ronald W
January 25, 2020 8:18 PM

so i installed this on a pu-18 board, it will boot the discs up to the black PS screen and then while loading i hear some sounds like grinding noise while the disc is seeking and wont go past that point….any suggestions?
i included a link to a pic of what i did
https://ibb.co/PcZM0pr

Ronald W
January 26, 2020 1:26 PM
Reply to  William Quade

genuine games still load fine. i figured as much, thanks for the response. any links that you can send my way to get the laser replaced? I will be buying more of your chips, they work great!!

Ricky260
Ricky260
February 6, 2020 6:01 PM

So… I have a PSX 5501 (PU-18 board)…. and I’ve tried to install the chip 12c508/P (04 SAW)…. But i can’t figure it out how to make it work…there’s no problem with original discs so the lasser is not the problem.
Please help!!!
Heres a pic of what I’ve done: https://ibb.co/ysHT2wP

Ricky260
Ricky260
February 6, 2020 7:15 PM
Reply to  William Quade

So based with the model of the chip I gave you (12c508/P 04 SAW)…is there a diagram for it???…P.S. That chip was working fine in a 9001 model.
thanks in advance

Ricky260
Ricky260
February 6, 2020 8:08 PM
Reply to  William Quade

Didn’t work…I guess I’ll buy a new chip. Thanks for everything

steven
steven
March 17, 2020 9:44 AM

It turns on but the disk barely spins at all (very slowly)

steven
steven
March 17, 2020 9:45 AM
Jeffery Law
March 28, 2020 10:18 PM

Thank you so much! Your chip and instructions were perfect and now my 5501 is modded!

Fábio Costa
April 9, 2020 6:02 PM

Good night. I have a ps scph-5502 pu18 and when soldering pin 5, it destroys the line .Where can I solder pin 5 alternatively? I hope they help me thanks

Fábio Costa
April 9, 2020 11:16 PM
Reply to  William Quade

Yes, there was a fine line up to the condenser, which in my case ended up disappearing. I will solder point 5 on one side of this capacitor and I hope it will resolve .. Thanks for the help.

Fábio Costa
April 10, 2020 5:36 PM
Reply to  Fábio Costa

Did not work. I don’t know what to do.

Fábio Costa
April 12, 2020 10:23 AM
Reply to  William Quade

OK. If you know any alternative tell me something.thanks

brandon
brandon
August 6, 2021 1:01 PM
Reply to  Fábio Costa

any updates on this? i think i’m having the same issue

Craig balaam
Craig balaam
May 2, 2020 3:27 AM

Hi successfully modded a Ps1 yesterday using your guide brilliant guide thanks

Bruno
June 7, 2020 3:39 AM

https://imgur.com/1ry2hzJ https://imgur.com/mLxMXQE https://imgur.com/zeOcO0R   Hello William, here are a few pictures of my install, i went with short wires as much as possible, obviously i surrounded the chip with electrical tape at the end.   I’m having issues with it, I’m noticing I’m having the same issue to a few comments here in the thread, the console gets stuck on the white bootup screen, the disc spins at first then gives up, and the white screen also flickers a few times, all these 3 problems I’ve read here too, I’m wondering what could it be since I think I did… Read more »

Andrew
Andrew
June 22, 2020 8:02 PM

I bought an mm3 from you off eBay. Installed to diagram on a PU-18 board. Put back together and disc drive wouldn’t spin. So I checked all my solder joints. Everything looked good, retried to no avail. Even tried disconnecting pin 4 and reconnecting it. Still no luck. Only thing I get is the white Sony boot screen but no disc spin. So I removed the chip and disc spins with no issue and boots up games. Any suggestions? Could the chip be bad? There is some melted plastic from we’re the wires were soldered to the chip. But there’s… Read more »

Last edited 4 years ago by Andrew
Andrew
Andrew
June 23, 2020 9:25 AM
Reply to  William Quade

Thanks for the quick response. The wires were short but I could probably make them shorter. I did recheck my wires several times (numbers run counter clockwise 1-8 from the chip notch per diagram) but maybe the wires just need to be shorter. I’ll try reinstalling it tonight and let you know. If it still doesn’t work I’ll buy another chip to try, in case I damaged it somehow bending the pins, before I give up. Thanks!

Leah Rowe
July 16, 2020 3:53 PM

yo nick, great guide! here’s my install i did earlier (some of it is using alt install points): https://pbs.twimg.com/media/EdBtSOrWsAAzKHl?format=png&name=large
EDIT wtf where did i get nick from. sorry, i meant will. not nick!

Last edited 4 years ago by Leah Rowe
Mr_Old_Skewl
Mr_Old_Skewl
September 27, 2020 10:26 PM

#0. With the gamefreax.de guide.

zero.png
Logan
Logan
November 13, 2020 3:22 AM

During installation I accidentally ripped the solder pad off of where pin 3 is supposed to connect.
How screwed am I?

Kon Dos
Kon Dos
November 17, 2020 8:22 PM

Installed mine today MM3 on Pu18 and also fixed the SCPH5502 from my girlfriend, discs spun twice and then did nothing, ended reflowing IC701 that fixed the issue.

No issues with the chip so far tried to make the install the cleanest possible, im still a lil bit afraid of the wire gauge used on these chips, will try a Mayumi 4 next.
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Aaron Waldorf
Aaron Waldorf
December 30, 2020 7:22 PM

Successfully installed the MM3 you sold me on a 5501. I used heat shrink tubing to cover the exposed legs of the chip. I followed your guide except for pin #1; on my PU-18 board there was an open pad just down circuit from the capacitor that I was able to use which did not appear on the picture you shared of your PU-18 board. It made the installation a whole lot easier! This playstation is now playing CD-Rs well with the exception of the FMV cutscenes which are very choppy in some games despite adjusting the laser potentiometer.

mm3Final.png
Massimiliano
Massimiliano
January 31, 2021 4:15 AM

I installed the chip on my pu-18, but now the console doesn’t turn on anymore. do I have to throw everything away?

Robert
February 23, 2021 3:23 PM

Hi man i did all like it seys on this websitw with my pu18 with mm3 chip and its shows me insert playstation cd when it is a playstation cd original
What should i do to play it right?

Robert
February 24, 2021 10:09 AM
Reply to  William Quade

Laser is new from china , chip is in place all wires are corect, is it laser isues ? it makes strenge noise thou

Robert
February 24, 2021 2:52 PM
Reply to  William Quade

Ok i will try, thanks

JohnDon
JohnDon
May 27, 2021 1:01 PM

Pin 5 is broken from the board for me. Is there any chance to solder it in another place?

Michael
August 30, 2021 3:03 PM

Just installed mine in my 5501 last night. Was my first time soldering ever and it somehow worked without a hitch, despite me being very liberal with the solder and barely knowing how to get if off the roll and onto the board. I did end up covering up my stripped wires with scotch tape cuz I stripped them too much and I don’t wanna short this thing. Yes, I did catch that short near solder point 4.

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Last edited 3 years ago by Michael
Irám Martínez
Irám Martínez
September 16, 2021 6:52 PM

Ola tengo una consola 5501… dentro de ella tenía un chip el cual es 12c508p 04 syx 0808 …. el chip No es mm3 pero lo conecte con el diagrama del mm3 y me funciono…. lo puedo dejar así ?

Por que los cables tienen que ser lo más cortos posibles??

Cuantos archivos hex para programar chips de ps1 existen aparte de los mm3 ?

Last edited 3 years ago by Irám Martínez