What is Rainbow banding and how can i tell i have it?

Also is it repairable?

Rainbow banding is when there are colored vertical lines going across the full length of your screen. The particular colors don't matter, it's the fact you have it is what counts.

A good way to test IMO is to get the Genesis to display a black/dark screen, say the SEGA logo on most Genesis games or the Sonic Team screen in Sonic 1.

Ok cool i dont have it.... pretty good considering my systems rear is smashed off exposing the motherboard and the power input is hanging by wires. I taped it all sealed shut with electrical tape and also position the power input to be stiff

http://www.sega-16.com/forum/showthr...ainbow+banding

oh gawd, i have it! Why does it only appear on "transparent" type things. My black screens and game screens are fine, but its the transparent effects in a game that make it show

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Originally Posted by salamando

oh gawd, i have it! Why does it only appear on "transparent" type things. My black screens and game screens are fine, but its the transparent effects in a game that make it show

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Yeah, it's common, but fairly easy to mod for without requiring all capcitors be replaced. (though that's recomended if you experience other problems like messed up audio and Sega CD crashing issues) Either an S-video mod, or a redone composite video mod will solve the problem, see: http://sega-16.com/forum/showthread.php?t=7796&page=26

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Originally Posted by salamando

Ok cool i dont have it.... pretty good considering my systems rear is smashed off exposing the motherboard and the power input is hanging by wires. I taped it all sealed shut with electrical tape and also position the power input to be stiff

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Sounds like you need to get a new Sega Genesis my man.

dont be a quitter baloo

I thought the waterfalls in Sonic 2 were how to tell. I went and they didn't work at all.

So I go see a waterfall in Sonic 1 and holy crap, you really do see it. Personally it gives the game an old school TV feel. :)

http://1.bp.blogspot.com/_vhk_t1jkZh...%2520Cover.jpe

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Originally Posted by Guntz

I thought the waterfalls in Sonic 2 were how to tell. I went and they didn't work at all.

So I go see a waterfall in Sonic 1 and holy crap, you really do see it. Personally it gives the game an old school TV feel. :)

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I think soem waterfalls in Sonic 2 work, the tubes in chemecal plant zone REALLY show it, I know the waterfalls in the first zone in Sonic 3 don't show it at all, but the one at the begining of Hydrocity does.

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Originally Posted by kool kitty89

You can see it in some youtube videos, I can't remember any specifically (but I know soem of mn12birds and CGR HD have it, I think MN12bird's Comix zone review shows it -especially at the boot/title sequence). There was a shinobi 3 video which showed it really well too.

Anyway, it's basicly thick vertical bands of iridecent colors, each around a 1/12 the width of the screen I think, and most visible on black screens and waterfalls (and similar) in the BG, the tubes in chemical plant zone show it quite clearly.

Edit: here at ~0:36 I think http://www.youtube.com/watch?v=oCDoP-zwoVI


I think s-video modding may eliminate it, and it's absent form RGB alltogether. I think the composite vs s-video vs RGB comparison TmEE posted recently shows the ranbow banding in composite, but it's not very clear.


The CXA1145 and 1645 encoders (the latter only on late model 2s and all model 3s) do have their own vertical banding tendancy, but shouldn't be visible in composite, and more like pin stripes (as on the NES -on a TV with really good comb filter- and famiclones), though I think those might be more broadly spaced than on the NES if that's what I can see on my TV. (which shows the NES's lines as well) They're very visible in s-video if a sufficient resistor (I think ~480 ohms) is not connected to the chrma line.

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If it only happens on certain effects used by certain games, then that to me spells "artifact of the specific game". It doesn't sound like it has ANYTHING to do with the Hardware.

You guys had me all freaked out about this for nothing! When I'm standing in front of the waterfalls in the first Act of Sonic the Hedgehog I see some 'rainbow artifacts'... but NO WHERE else in the game.. and I don't see those artifacts in any of the other 27 games I have.

Guys, it's called an Engine Artifact.


Just because a certain game on the PC has graphical issues doesn't mean there's something wrong with the hardware.

It's an issue with certain games, and so far I've only seen it on the bloody waterfalls of STH.

You can see it in most cases if you get the Genesis to display a black screen.

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Originally Posted by Guntz

You can see it in most cases if you get the Genesis to display a black screen.

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Funny, mine doesn't do that on a black screen. It only does it on Sonic the Hedgehog in the first world when in front of the Waterfalls.


I'm soooo relieved to learn that this was some weird 'console crowd based' misconception... you guys had me thinking there was potentially an issue with the Hardware and I come to find out it's related to specific games.. of which I've only seen it in one out of 28 so far.

It is a hardware issue, and occurs in every single game, it's just not always very noticeable, many waterfall effects show it, but not all, as do a variety of other transparency effects, liek the tubes in chemical plant zone in sonic 2. It seems to be caused only on consoles witht he CXA1145 video encoder, probably due to aging capacitors on the board. (this includes Model 2s) It's almost invisible in PAL video though.

It is not present in s-video mods or Ace's new composite video mod, and again, only occurs with that one type of video encoder chip -AFIK. (that mod is listed in one of the recent pages of Age's genesis model guide, but is basicly a 100-220 uF capacitor connected to the composite pin of the CXA1145, then a 33 Ohm resistor, then connect that to the composite video line on the AV port and/or RF port) The removal of the artifacting is an added bonus, the main purpose of the mod is to give sharper video. (as with the s-video mod)