PM-41 ONEchip modchip installation diagram
.Towards the end of the PlayStation 1’s life Sony released a slim model called the PSone, or SCPH-10x. Many of these systems have PM-41 boards inside, which is what this page covers. Some of the boards are PM-41 (2) and require you to use a different diagram. The model is printed on your board if you take apart your console.
For more information about ONEchip chips click here, for more information about PS1 modchips click here.
PM-41 ONEchip modchip installation diagram
Above is the installation diagram. It is from FatCat.co.nz.
Installation tips
Here are some tips I have for you when you are soldering your chip into the PM-41.
- Cut your wires to be as short and direct as possible.
- Pin 2, 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 wires you are soldering don’t come into contact with other components or legs of chips.
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.
- None yet.
The original un edited diagram comes from FatCat.co.nz. you should always give credit where credit is due
http://www.fatcat.co.nz/psx/install/102/ONEchip8.html
I added a link to the source of the image. The diagram pack I got it from had already edited out the source information.
Hello again
Do You know if length of wire affects only booting games? Or it could also affect reading discs?
Cheers
I haven’t done extensive testing with long wires myself, but from my experience with helping people with installations that don’t work, yes. A common thing people run into is the disc will spin super fast and not read. I always tell them to shorten the wires to be as short as possible, and to check the board for any shorts or solder bridging connections it shouldn’t be. Long wires are more likely to pick up noise from other sources (both inside and outside of the console) as well as introduce noise to other parts of the system. Long wires will… Read more »
Thanks. While everything works I have a weird feeling that console more struggles with certain discs.
Hi! Just successfully installed this modchip on my PSOne, works a treat!
Hello, I just used the diagram and it seems to have worked fine. Only issue I found was with the PSOne not recognizing genuine and burned games the first few times I tried. But after it stopped playing up it just worked. Is this normal for the onechip. will the PSOne play the NTSC games at 60htz?
The system should output 60Hz when playing NTSC games. It should boot games every time you start up the system. Some things that can cause issues are worn out lasers, and wires that are too long. A decoupling capacitor can help improve reliability too.
The wires are as short as possible, quite proud of the work actually. I drew inspiration from the Youtuber Voultar. Here is a link, if its clean enough feel free to share it on this page https://imgur.com/a/WBzmZUi . I don’t think I have a worn out laser, but can you explain in more detail the decoupling capacitor please? I just tried it out again and got an instance of the red screen asking for a playstation format disc, did a reset and the game played fine. Is this a faulty mod chip or is it still possible that I may… Read more »
Those wires are probably short enough, some of the connections could be cold solder joints though. A decoupling capacitor is a small capacitor (something like a 100nF or 0.1uF ceramic capacitor) connected between the VCC and GND pins (pins 1 and 8). It’s definitely possible that the chip is defective or programmed incorrectly.
Did the system read genuine games fine before? Does it have issues with genuine games with the chip installed? Genuine games are easier for the laser to read so if it is able to read genuine import games every time then the laser would be the issue.
Yes the console did read genuine games properly before the mod. And yes the system did not recognize the first genuine game I put into it after the mod, but did after the reset. Also I have a few backups from someone that sold me a psx ages ago. These games are difficult to get going and some of them are read as music cd’s. Any back ups I have made are easier to read, still needing a reset sometimes to get it going. I don’t have any genuine import games to try with it. But yes I can understand… Read more »
Yes, because the cold joints can cause intermittent connection issues. Reheating them with extra flux added should be able to make the connections better.
Ok, thanks William. I will re investigate the install and let you know how I go. Thanks.
I know ONEChip because of you, thanks!
Installed it successfully in a PM-41 board. Install was tricky because point 5 was gone from previous modchip and we had to wire it up from the main CPU, but at the end is a success!
I’m having some issues getting a ONEchip to work in my system. I’ve programmed a couple PICs at this point and they all seem to do the same thing. The reset line is held down when the disk tray switch is pressed, meaning the console does nothing while the tray is closed.
Sounds like an issue with the programming of the chip.
That’s what I’m thinking as well. I’m using a TL866A with its matching software, and this is how the chip is set up to be programmed: