Neo Geo AES RGB Video Info
There's already a few pages on the web that detail the various different versions of the AES and their RGB output quality - here's just one. I'm in the UK so lucky enough to have TVs with an RGB Scart socket, so of course wanted to use RGB for the NeoGeo.
The motherboard in these photos is a late one - a NEO-AES3-6, to be honest - when I tried it unmodded using an RGB lead on my portable TV it didn't look too bad. But when I tried it on an a larger LCD it looked awful, with terrible vertical lines.
I originally wrote this page with info on how to perform the RGB bypass (and the info for this can still be found later on down the page if you still need it). After I contacted MKL on the Neo-Geo forums he pointed me to one of his posts with info showing that cutting 3 traces on the underside of the motherboard is all that's needed, a lot easier than performing the RGB bypass :) It's brilliant! NO SOLDERING REQUIRED, JUST SOME SIMPLE CUTS.
Here is the original post with some photos, here's a few photos of my own to compliment it (I did this AFTER replacing the components removed during the RGB bypass)
The first photo above shows the RGB output BEFORE doing any modification. The second photo is AFTER with absolutely no vertical stripes down the screen :)
The area you need to work in is on the underside of the motherboard, directly underneath the crystal (the cause of the problem) that is near the AV socket and the Sony CXA1145P video encoder.
Here's what you need to cut, I cut both sides of the traces - this is probably unnecessary and I should have experimented but cutting both sides definitely did the trick. The image quality was even better than the RGB Bypass I previously tried.
It really is as simple as that, a big thanks to MKL for discovering the information and sharing it with everyone.
50/60hz????
There was conflicting information on if my NEO-AES3-6 was outputting a PAL or NTSC signal. Since I was using RGB I wasn't really worried about how the colour was encoded, but I definitely did want 60hz output!
The area marked NTSC ONLY confused me, as I was sure (but couldn't prove) that my console was outputting an NTSC signal, but this area had no components. You'll notice a metal link on the Sony chip in the top right of the photo, after poking around with an continuity meter it's easy to see that it's grounding a pin on a nearby chip.
Just like the Megadrive and SNES 50/60hz mods which work by supplying a GND or +5v signal to a specific chip, I guessed the same might apply here. So I removed the metal link, powered on the console and nothing had changed. Next I linked the 2 pads in the PAL square, the upper one was measuring 5v, switched the console back on and sure enough I had huge black borders top and bottom of the screen.
So if the leg 64 on the nearby chip - LSPC2-A2 9305 E27 is left floating (not connected to anything) or has a GND signal then it's 60hz, if it is linked to 5v then it's a 50hz signal. Here's a photo showing the chip in relation to the pads.
If your Neo Geo motherboard doesn't support the method above, it's possible to bypass some of the components to try and improve RGB quality. All of the info you need can be found on the Neo-Geo forums, with info originally posted by MKL, I wouldn't have known about this if it wasn't for the postings on that forum.
Here's a few photo's of the my mod, and a few notes I made whilst doing it.
The first photo above highlights the components to remove (highlighted in their relevant colour), the second photo is after I have carefully removed the glue using long nosed pliers.
Here it is after desoldering the parts. It's quite easy even with cheap equipment. From the underside of the board I simply heated the solder on each component leg and then used a desoldering pump to remove the solder. If necessary I added some extra solder, you may find it easier to straighten the legs of the components that you need to remove.
I've read on a couple of forums, and it's been recommended to me by a couple of pro modders to fit resistors onto the RGB wires, I used 75ohm, attached to short wires and then heat shrinked. It probably would have been possible to just insulate the resistor legs instead of cutting them and attaching them to wires - I just wanted to show you the colours!
I started with the Red and Blue signals, I found it easier to do Blue BEFORE Green - it's obvious if you look at the photo above. Make sure you tin the wire and resistors, and even add some additional solder to each of the contact points you need to use. You can also see the Yellow Sync signal.
There we have it, nice and simple really. Doing it this way will remove composite, but will let you use your existing RGB Scart lead, a big thanks again to MKL :)
