PS1 MM3 - not booting in stealth?

Hi all,

I installed a MM3 chip using the diagram on William Quade's site (https://quade.co/2017/pm-41-2-mm3-installation/) but games with copy protection still boot to this screen: http://i.imgur.com/fHB7rYD.jpg

Every other game works fine. My understanding is that booting it with the lid closed should put it in stealth mode, but I tried it both ways to be sure, with the same result. Any help would be appreciated. Thank you!

 

I would start by removing the wire on pin 2 of the PIC, since the MM3 doesn't need it and it might be interfering with the mechacon clock.

Other things you can try:

Moving the pin 1 wire from the 5V regulator output to the 3.3V rail (same point that pin 4 is connected already).
Moving the pin 3 wire from the resistor it's currently soldered to to the one just to the right of it - this makes the stealth code cut off the data slightly earlier.

Having said that, modchips on the PM41(2) board seem to be problematic at the best of times.

 

MM3 install diagrams:
https://imgur.com/a/nhZmf

Have you tried this instead? I noticed there is no pin 4 in this one though (lid?). I would try disconnecting it anyways, see what happens.

But 2 is not needed. That's a borrow from the Mayumi diagram.

 

Mm3 diagram is wrong. Move point 3 as trimesh said.

Will work then.

 

I can update the diagram once it's been confirmed by OP to be working.

 

Pin 4 is the RESET/ signal - since the PSone doesn't have a reset button, the best thing is just to permanently tie it high. It's not actually being used as MCLR/ in this case, just as an input that's used to switch operating modes. Pin 7 is the door switch.

 

Thanks TriMesh.

 

I can confirm it's working after moving #3 to the resistor directly to the right of the one I had it soldered to. Thank you!

 

Corrected diagram.