Neo Geo AES 3.3 interferences on screen

I have changed recently caps and resistors on my console to optimise RGB contrast. I discovered I have some very light image distortion vertical-diagonal lines on RGB. I also have black and white composite.
My motherboard is 3.3.
Can anybody help?

Update:
Put the console to my other BVM crt and the color is fine. I suppose there where some settins that wanted adjustmentn to the previous BVM crt...
Now about the diagonal lineswhich are like interferences shape.
I changed the jpn PSU, that worked with a converter 220v to 100v, with a pal SNK original PSU 5v 3A I found on ebay and the lines became less. Then put the PSU's electricity cable to an APC surge/arrest protector and lines became very hard to spot. Maybe if I didn't know I wouldn't have seen them, but still there.
If I remove the phones stereo jack that leads to a speaker system lines become very angry again. Poor image.
WTF is going on?

Are you using composite video for sync? This can cause interference in your image like you describe. Use composite sync with a buffer instead, it should help. A nice shielded cable is good too.

RockstarRunner said:

Are you using composite video for sync? This can cause interference in your image like you describe. Use composite sync with a buffer instead, it should help. A nice shielded cable is good too.

Click to expand...

I have connected the Neo using bnc male to scart female cable that I bought from someone making them in UK. I had an RGB cable without shield but then I bought another with shield. No difference.
If I use just composite there are no interferences. In RGB there is the problem.
My jpn N64 connected with S-video has also a slight interference problem.
My pal megadrive RGB, pal Gamecube RGB, pal wii component, pal Xbox 360 component, have a clear perfect image.

What is "composite sync with a buffer". I think this might be the key for my problem. I have lots of AES games that look shitty...I can't get a 100% satisfaction from my NEO
I also aquired a super famicom with RGB cable but had no time to check it out...

For a 3-3, I recommend an RGB bypass as the RGB output is so dim on a 3-3, it should also eliminate any artifacts. On some occasions I've even added a video amp.

Xian Xi said:

For a 3-3, I recommend an RGB bypass as the RGB output is so dim on a 3-3, it should also eliminate any artifacts. On some occasions I've even added a video amp.

Click to expand...

How I am going to do that. Do I have to cut some traces?

You don't need to cut anything. Just run the RGB signals before the 6.8k resistors to the AV socket.

Xian Xi said:

You don't need to cut anything. Just run the RGB signals before the 6.8k resistors to the AV socket.

Click to expand...

Is it the same as your guide: RGB Bypass Mod for Your AES Board Revision 5 to 7 ?
Are they the same pins? If yes, the only thing I have to do is to just wire those pins togeather, like blue to blue, green to green etc? Do I need to also connect the 82ohm resistors beacause I have changed caps from 100 to 470 and resistors to what Sony recommends.
Thanks James

Green Beret said:

Is it the same as your guide: RGB Bypass Mod for Your AES Board Revision 5 to 7 ?
Are they the same pins? If yes, the only thing I have to do is to just wire those pins togeather, like blue to blue, green to green etc? Do I need to also connect the 82ohm resistors beacause I have changed caps from 100 to 470 and resistors to what Sony recommends.
Thanks James

Click to expand...

One of the cleaner ways to do it is pull the caps up a little about 4mm off the board and stick out the leg that goes to the encoder and then solder a wire from the leg to the appropriate 6.8k resistor for that color.

Xian Xi said:

One of the cleaner ways to do it is pull the caps up a little about 4mm off the board and stick out the leg that goes to the encoder and then solder a wire from the leg to the appropriate 6.8k resistor for that color.

Click to expand...

I want to understand your mod. The mod is to remove 3 caps, red, blue, green for ever and then connect the minus of where the cap was with the 6.8 resistor of each color like this pic Sorry but I am a rookie at electonics.

But you suggest for a cleaner way just to put out the + positive leg of each cap and solder a wire from the leg to the 6.8 resistor.
I can leave the sync cap as it is to have composite. Is it correct?

Do I need to do also wiring to the back of the board?

Correct, just pull out the positive leg and solder to it. Keeping the cap in the circuit helps with the ac coupling. You do not need to remove the 6.8k resistors btw.