New OSSC owner, some bad problems.

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    I got my OSSC today and i was eager to try it so i went at it.
    I will try to explain things as best as i can, but english is not my native language.

    Thing is i own a Mega Drive, Saturn, Dreamcast, Snes and N64.

    In preparation for the arrival of the OSSC i ordered cheap RGB Scart Cables (i know this may be the cause of my issue, but just want to ask more knowledgeable people here)

    So the OSSC works good with my TV it seems, almost all modes work and the image is good but the following problem occurs.

    I get some wide noise lines that go from the botton to the top of my screen (they move) diagonally, a lot of them depending on the console being used with the worst one being the mega drive.
    It can be seen better on black backgrounds.

    I already tried another monitor and the same thing happens.
    Hooking the mega drive directly to a CRT, same Scart cable, i can’t seem to notice it.

    So i’m wondering if it’s the cables fault or i got a faulty OSSC?

    Tried to capture it in video here.

    I recorded a more obvious video.

    Thanks a lot for your time!

    EDIT: I think it’s pretty clear from the video what i mean, but it’s much worse in person.


    I am not an electrical engineer, but I would say it’s the cables. Very cheap AV cables often have no shielding whatsoever, and RGB SCART cables, in particular, are susceptible to noise from the composite video line, which can manifest as visual noise (such as what you’re seeing) and audio hum, notably on all-white screens.

    I recommend quality, fully-shielded cables from Retro Gaming Cables in the UK or Retro-Access in the US. To make sure that it is indeed the cables, I would pick one console and order a quality cable for it; if the better cable solves the noise problem, go ahead and order cables for the rest of your consoles.


    I would also say it’s the cables.

    But just to exclude other problems: Do you use the default power supply for your OSSC and your consoles? This looks somewhat familiar to me, a Megadrive looks just like this when you use a bad power supply.


    Thanks for your answers.

    – I’m inclined to say it’s the cables too, they are cheap and as you said i checked for audio hum and indeed there’s a massive audio hum on white screens (or any screen other than black really)

    – I do use the default power supply for OSSC as i ordered it with the device. For my consoles i do use the default one too except for the mega drive, but the problem is showing with all the consoles, not just the mega drive (it’s just worse with that one)

    I bought all the SCART cables for all the consoles in the same store and they were all equally cheap.

    Edit: I decided to open a cable, here are the results!


    It is impossible that noise in the black background is being caused by the SCART cable. Usually you see interference from Chroma signal on composite video but that is visible as non-moving diagonal lines in colored backgrounds.

    There is no Chroma on a black background so that can’t be interfering.

    If it happens with all your consoles then most likely it is a faulty OSSC.

    Have you tried another HDMI cable?


    I have tried another HDMI cable, another monitor, another plug.

    And yes, as i said it happens with all the consoles but the videos are from the mega drive in which it’s a lot more noticeable.

    Edit: I just used my Saturn again, to test, and indeed the problem is MINIMAL on that console. It’s still there but you have to be actively looking for it to notice.


    If you got your OSSC from us please e-mail in and we’ll exchange it for you.


    Yes, i got the OSSC from you, i’m waiting for a friend to come by and lend me another power supply for the mega drive to test.
    I will report back and / or write an e-mail.

    BuckoA51, have you seen the same issue with another OSSC units? Just so we can know if it’s indeed a faulty one.

    Thank you.


    Ok, i’m gonna update the situation.

    I tried the mega drive with a new power supply and the problem dissapeared!
    So it seems my OSSC wasn’t faulty after all?
    So now that the big thing is out of the question i’d like to ask.

    If i get REALLY close to the screen, i can see some white dots randomly flashing on the screen (specially on a black background), almost impossible to see at normal viewing distance, is this expected / normal behaviour? I tried to capture it in a video but it’s impossible.

    Thank you!


    Some Megadrive 1 revisions are very picky. Do you have a Model 1? Is the other power supply an original from Sega? While they are not the best ones, they cause the fewest problems.

    But this doesn’t explain, why the other consoles look bad.


    The other consoles stopped exhibiting the problem the moment the Mega Drive psu was unplugged from the socket. So i’m guessing that psu was doing something really ugly causing electrical interferences.

    And yes, i have a model 1. The faulty psu was a third party one, and the new one i tried with is a third party one too.

    So as i mentioned above the only “issue” i can see now is some white dots (pixels) flashing randomly on the screen, but it’s barely noticeable unless you are like really close to the screen.


    The white dots will go away with a Sega power supply. Most 3rd party PSUs too weak. But before you look for a 25 years old Sega PSU, consider that it is unregulated and your Megadrive will get unnecessary hot with it.

    I have a 3rd party 9V 1.3A PSU from and while this should be more than enough it still gives me small white dots. But I never thought about replacing it, the dots are barely noticable and the Megadrive doesn’t get hot with it.


    So what’s lacking with that 9V 1.3a PSU? Too little voltage? Too little amperage?


    I don’t know, 1.3A should be enough. My Genesis (High def) doesn’t show the dots with the 1.3A supply. My Megadrive (non High def) does. The dots disappear when I use the original PSU or a 9V 2A PSU, but I need the latter for my Gen/32x Combo. So I think it’s the amperage, but this doesn’t explain why the original 1.2A works good. Anyhow, it’s not worth to fiddle around with it since you only see them if you are VERY close to the TV.


    Yeah i guess it’s not worth to fiddle around, the big problem dissapeared and it seems the culprit was found so i’m gonna assume the OSSC is not faulty at all i guess.

    I will keep observing it for anomalies anyway, it has a 1 year warranty so i’m not really worried 🙂

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