Neo Geo AES Video Issues?

Before I begin, I apologize if there is a post here on helping out with this issue. I did search here but didn't see anything specific about this, or I may have overlooked it. And sorry for the long post. Just wanted to get all the information out there.

A friend of mine recently won an auction on Goodwill's website that had a Neo Geo AES up for grabs with all the parts and accessories along with two games.

He just received it yesterday, and I headed over to check it out as well as I was waiting for mine to return from some mods I had done on it. We tried out a couple of games, and noticed a few issues.

The biggest issue was that the colors on screen seemed to create a psychedelic effect, where the proper colors would show up for a brief moment, then would start to change and hue to different colors. For instance, the SNK blue on the main start would be blue, but would then start to change to a purple color followed by a green. And throughout any game, the colors would seriously create a weird effect, like the green bamboo in Samurai Showdown would change to a brown followed by a red then back to a green and repeat. Other games created a similar effect, although one wouldn't work at all, League Bowling. On boot, the game would have a garbled graphic and not even start. I'd have to take the cart out and reset it like two or three times before it would work, but I wasn't getting any sound. The other games, Samurai Showdown & Magician Lord, would play audio but have the graphics issues..

I remember reading somewhere online about troubleshooting issues based on what the screen displays without a cartridge in the system, but I get a random pattern of colors that it is impossible to figure it out. Can't remember where I read it, so if that wasn't a good idea, I hope I didn't harm the system.

He also has a Neo Geo CD and that system works fine with his television. He's using composite cables on both right now, and is contemplating upgrading the video out on both soon. (For the record, he's using a Panasonic Plasma.)

Sans a possible television issue with this system only, what should he do to solve or look into the issue further? Or is there anything additional information anyone would need to help with a solution. Thanks!

Clean the slots.

Thanks. I will let him know to try that. I feel kinda stupid for not thinking of that last night.

Of course, after a beer or two, you forget the logical things to try to fix the issue.

I wonder if it needs recapping. When I had the wierd image bending issue with my 1st gen AES I swapped out 5 of the 100uF caps for the RGB, sync and composite outputs and that solved it. I then tested the old 100uF caps and they were all measuring less than 50uF, most less than 40uF. Could well be the capacitors.

Well, I let him know to try what Xian Xi had suggested. Like I said, I can't believe I didn't think about that first. He responded that he hasn't tried that yet, but hopefully he will get a chance to do so soon.

If that isn't it, I will pass along the recapping issue as a possibility. If I find out what the board model number is from him, I will post what it is and probably ask for more insight if that is alright.

I appreciate your insight guys, and thanks!

Be sure the power supply is in good condition. Noisy power supplies have caused video encoding issues on a lot of systems. It happens frequently on Sega Genesis and SNES systems with cheap, poorly made third party adapters, where using a better power supply immediately resolves strange rainbow banding and interference patterns.

Replacing capacitors is never a bad idea as well.

I remember checking the power supply to see if there was a humming noise coming from it. I didn't hear anything that seemed normal, but I will pass that along as well.

Still no word yet from him, but I think that is because he is still tied in to his CD system.

Thanks for the tip as well!