SNES Mini RGB Mod "Slight Rolling Brightness"

[Josh128]

I did the straight wire mod with resistors on the mini, using composite sync I wired from the mainboard to the proper pin on the multi out, and it makes a great picture, no vertical line problem, no jailbars, but there is just the slightest hint what I can only describe as "rolling brightness changes" which are almost invisible to the eye, but on some full screen colors (light blue, light tan, etc) , I can notice them, most easily on light blues. Very, VERY slight, and probably 90 out of 100 people wouldnt even notice them.

Im going through a CSY-2100 clone and cant detect this on either my NESRGB frontloader or my 7314 modded N64, but I have noticed something similar on my original model Genesis. This is a very ,VERY, slight issue, but it bugs me a little bit. I could also describe it as "rolling or wavy luma". Was wondering if maybe I could try another power supply, or if maybe bypassing the encoder and using the 7314 amp mod on it might alleviate this?

Does anyone else have any clue as to what Im describing or what I can do about it?

[ApolloBoy]

What value resistors are you using?

[antron]

Are you using an official power supply?

[ApolloBoy]

Are you using an official power supply?

That's also important as well. If you're using one of those shitty "3-in-1" AC adapters, you're going to get some interference. The reason being is that most American SNESes lack a big filter capacitor on the motherboard, which is what all European and Japanese systems have. Nintendo opted to put the filter cap inside the AC adapter, and those cheapo ones lack said filter cap, which in turn means that any interference or ripple created by the PSU will get passed on to the console.

[Josh128]

Official power supply that came with my original SNES 1. I believe it was 75 ohm resistors. When I say slight guys, I mean ever so slight. Its like 1 inch tall horizontal lines of extremely slightly varying luminance rolling from the top to the bottom of the screen pretty quickly, almost like rolling waves, but with no picture distortion, just a little variation in luminance. Even knowing they are there, I sometimes have a hard time spotting them-- otherwise picture is magnificent.

Im leaning toward the power supply, but it is the original one that came with my first SNES some 22 years ago. I might try that first, and if that doesnt do it I may try to bypass the encoder with an amp.

[Josh128]

Well, got an OEM power supply on the way from Ebay, I needed one anyway as my Mini did not come with one, had to steal from my childhook SNES 1. Will update with results when I get it.

[Josh128]

Sorry I never updated. The new OEM powersupply I got from Ebay made no difference. Must just be an analog signal thing. Its essentially a non-issue though-- Ive since noticed the effect on most (not all ) of my analog connected systems. Its so light and infrequent that 99.9% of people would not notice it. Apparently not a SNES problem.

[ApolloBoy]

Try bumping up the resistance on the RGB signals to 100 ohm, that might mask it a little bit.

[Xan]

I never noticed anything like that on any of my consoles, ever, and I do look for stuff like this. Is this visible on various displays? Does it happen with other connection types (S-Video, composite) as well?

[Josh128]

I never noticed anything like that on any of my consoles, ever, and I do look for stuff like this. Is this visible on various displays? Does it happen with other connection types (S-Video, composite) as well?

I really dont see it on my NES , N64, DC, or Wii or GC. Actually the last few times I played SNES and Genesis I didnt see it, either. Its very slight and generally only occasionally noticable on certain colors, such as rich screen filling blues. Only ever connected converted RGB to my plasmas.