Neo Geo AES Rev 3-5 RGB Bypass Issues

I followed the tutorial on the below link for the RGB bypass for Rev 3-5.

http://www.jamma-nation-x.com/jammax/tutorials.html

This is the rev board I have and I have followed everything in the picture. I have installed 82ohm resistors where its mentioned below.



At the bottom of the page it says:

RGB seems to be working fine after the mod. Composite however is displaying in black and white.

I've done exactly what is shown in the tutorial and what is mentioned above re keeping composite.

Either I have done something wrong, or they have not tested this mod with composite as mention above.

Any help is appreciated.

 

Are you playing NTSC games on a PAL console or PAL games on a NTSC console?

 

This is a PAL console and the cart I have is NTSC.

It's worth mentioning that I have installed a UniBios 3.3 earlier in the day.

Another thing worth mentioning, is that I have just received this console and it is my first ever AES. I do not have a controller to mess with the bios settings. Controller should arrive in the next few days.

 

The black and white image is to do with the colour encoding on the Composite signal, not the unibios mod or bypass. PAL has a different colour carrier frequency compared to NTSC so there is a mismatch which your TV/ monitor cannot decode. This results in a black and white composite image. RGB is read directly by your TV/ monitor so the colour is ok.

This can be solved by either feeding an NTSC frequency (3.58 MHz) to the video encoder or installing a dual frequency oscillator. Composite is poorer quality so I would stick with RGB.

 

Thanks. I understand now. Pal consoles are always a pain in the ass to mod.

I'd rather have both composite and RGB. I remember reading somewhere the bypass mod would improve the composite. That's mainly why did it. I guess I will be reverting the console back. The RGB signal isn't even bad at the moment. Composite however has this slight wavey effect on text and some colors, but I can live with it.

 

As said above, the bypass doesn't change anything like that. If it's black and white now, it should be if you revert it (or have been before you started)

 

I'm getting full color without the bypass on composite. After performing the bypass mod, composite stopped outputting color. I just reverted back and got color back.

 

Then it's nothing to do with the colour carrier frequency or the game being ntsc vs pal etc.

Edit, looked into the mod. It's bypassing the video encoder so you wont get a composite picture. This is expected behaviour and it's mentioned in the tutorial too.

"**Note: After having done this mod, your Neo-Geo will no longer display composite out video from the onboard encoder! Only RGB."

 

Why prefer composite over RGB? I believe the AES uses the CXA1145 encoder which outputs the worst composite signal possibly.

 

At the bottom of the page, it says:

After doing so, composite outputs black and white.

 

I would rather have both outputs because I will not always have RGB. My 50KG PVM is hardly portable

 

That's interesting. How were you hooking up your AES before the mod? Composite will always give black and white picture when displaying a different video standard game to the console (PAL - NTSC). Do u have pictures of your install?

 

I am using a Sega Genesis 1 AV cable. I reverted the console back by reinstalling the caps and resistors I took out for the bypass. As i mentioned above, I am getting full color through composite.

I will snap a pic of the board when I have a chance.

Could the console be modified already to display NTSC in color? I didn't notice anything out of the ordinary, but then again, I am not that experienced with the AES. I will have a closer look at the board, maybe I missed something. The console for sure was opened before I got it.