PC Engine RGB
Many years ago Saurian from NTSC-UK passed on some info on getting RGB from a PC Engine. It's taken me a while but I finally bought a PC Engine and have tried out the RGB Mod.
I only have the original White PC Engine, so can't confirm exactly what's needed on the many other hardware versions at the moment. You do need a 4.5mm Gamebit to open up the PC Engine.
Once you have opened the console up, you'll notice some shielding on the bottom of the motherboard, this is soldered into place and it easy to remove. The photos below show the 2 different kinds that I've seen and the spots marked in red to heat up so you can remove the shielding.
There's 2 areas that you can get the RGB signals from. The easiest is the Ext Bus solder points and because this guide is for the PC Engine that's what I'm going to use. If you are modding a different model without the Ext Bus, then you can get RGB from the Hu6260 chip (or in my case, HuC6260) and audio etc from the existing din socket.
I've seen 2 motherboards, both label the Ext Bus pins slightly different, I prefer the one that is labelled A1-A23, B1-B23 and C1-C23, so that's how I've labelled the photo below, you can see what's what in the table.
| Signal | Ext Bus | Hu6260 | Scart Plug pin |
| Ground | A21 | - | 4, 18 and 21 |
| Composite Sync | C22 | 44 | 20 |
| Red | A23 | 49 | 15 |
| Green | B23 | 47 | 11 |
| Blue | C23 | 51 | 7 |
| 5v | C21 | - | 8 |
| Right Audio | A1 | - | 2 |
| Left Audio | C1 | - | 6 |
Now it's time to prepare the motherboard. The method that was recommended to me involves removing the RF Unit and placing an 8 pin mini din socket in its place. To remove the RF Unit, I added a small amount of solder to each of the 3 tabs that are soldered through the board, they are part of the RF Unit casing. I then heat them up and using a desolder pump I remove as much of the solder as possible. Once they are as empty as possible, I remove the solder on the 3 contact pins that are supplying the Audio/Video signal to the unit.
Take your time doing this, and you should be able to remove a lot of the solder. I couldn't get all of the solder out of the 3 large points, so I then VERY CAREFULLY levered the RF Unit off. I placed a flat screwdriver in between the RF Unit and the motherboard, and then whilst heating the solder I twisted the screwdriver. I can't stress this enough, you have to be careful not to damage any of the components near the tabs. PLEASE, Please, please be very careful. If you know a better way of removing the RF Unit please contact me.
Once removed you should find it easy to remove the extra solder from the holes, if you can heat it from one side and use the desolder pump on the other side you should be able to remove it all in one suck!
Now, some people add a standard size 8 pin din socket the PC Engine, sometimes this involves mounting it in the case, or making the hole in the case larger. Saurian recommended fitting a Board Mounted Shielded 8 pin Mini Din socket (it's actually the same as the controller port). Once fitted you don't have to modify the case at all, so it's very very tidy.
