Neo Geo AES Picture Flickering

[BluntX]

Hey guys, wondering if I could get some insight into a problem I've been having with my Neo Geo. I just hooked it all back up today to a newly purchased Sony Trinatron CRT and I've been getting a lot of flickering with the picture. When I got the machine a couple of years ago the picture would occasionaly flicker but only once or twice and only during certain game intro movies - never in game. Now it's very common.

I've tried both the original Japanese 110v PSU and my locally sourced 220v power pack, connecting it up to the TV with bog standard AV cables and through an XNEO-1 box, different games - no dice, still get nasty flicker. The only thing I've noticed is that if I move the PSU's plug whilst it's connected in the back of the machine and powered on (not pulling it out, just rotating it) I'll get the flicker or complete system reset. Could it be a dodgy power connector on the actual Neo Geo board? Any help would be greatly appreciated, it's driving me nucking futs!

[Oldgamingfart]

It does sound like the socket may have dry solder joints. Occasionally the socket itself can get dust trapped inside it, or become a little corroded over time.
Before taking it apart however, try giving the socket a clean with a slightly damp cloth inserted with the help of a precision screwdriver or hairpin. The 'barrel' of the plug itself can be cleaned the same way.

[BluntX]

The plot thickens. I cleaned out the power socket as you recommend Oldgamingfart and even gave one of the cartridges and the slot on the Neo a swab. Initially everything seemed fine then the flickering returned. Bah!

Out of curiosity I hooked the console up to my Sony LCD and let it run for a while. No flickering! Ooooh, maybe it's fixed itself? Hooked it back up to the Sony CRT - flicker says "sup?". Double Bah! Hooked it back up to the LCD just to see if it was a fluke but got a steady (albeit ugly as sin SD signal on an LCD) picture. I've now got it hooked up to an old NEC CRT and I'm not getting any flickering but will occasionally notice a tiny bit of screen shake (as in the picture moves a pixels width up and down every so often) but nothing that gets in the way of gameplay unlike the flickering on the Sony CRT.

I have noticed that when it is hooked up to the Sony CRT and I get the flicker, the Input name in green text will flash up in the corner of the screen as if I was changing inputs or the TV is losing then gaining the picture signal back rapidly. Sound is unaffected. The strange thing is I get no problems at all running my Wondermega or PS2 on the TV.

[Oldgamingfart]

Hmmm, now that does sound like an odd one. Maybe the Sony is a bit more sensitive to poor sync or noise.
I still think there's a loose connection somewhere, as your first post indicated the problem was brought on more rapidly with movement. The A/V cable itself could also be the cause.
I guess for now you could try another A/V input, or maybe try running it through a VCR or DVD Recorder.

[BluntX]

Aha! Just had a bit of a break through via a combination of trial and error and that moment of clarity one gets whilst having a few down at the local, boring his mates stupid about his problematic game consoles and scribbling very important notes and diagrams onto napkins with Keno pencils.

I went into the Sony's service menu and noticed that when the Neo Geo was on, the picture geometry was changing. Had a bit of a play with that but nothing would work but then I saw that whenever the picture flickered it seemed to go to 50hz then when it stabilised it would go back to 60Hz. I started going through each of the service menu options, all in 3 letter code so kind of hard to figure out, and I found an option that seems to lock the TV to 60hz;

YCT 16 CDM 00 (This is the default. I'm guessing auto detect for 50/60Hz)
YCT 16 CDM 01 (What I changed it to. This seems to lock it to 60Hz)

Going to keep playing around carefully but I'll admit I fist-pumped the air and scared the **** out of the cat when I yelled out in satisfaction that the flickering picture seems to be gone.