PSone No Sync

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    I recieved my OSSC this week and tried it out for the first time today, but I’m unable to get any picture at all most of the time.
    I’m using it with a PSone (SCPH-101, NTSC model) and a regular sync on luma cable from retrogamingcables (this one:

    The OSSC just displays “NO SYNC” with very infrequent drop ins. Tested it with two different TVs (Sony W705 and X900E) and two different HDMI cables.

    What’s strange though is that it doesn’t always behave like this. Sometimes I get sound only while the video output still shows the test screen and earlier today (after 5 minutes with no sync) the signal suddenly became stable while trying out Breath of Fire III. Switched to BoF IV -> no sync again. I could not replicate this again and didn’t change any of the settings, but I sometimes get stretches with a stable signal.

    Speaking of settings: I tried to adjust the H-PLL values (and all of the other sync options) but it didn’t make a difference.

    I don’t have access to other consoles with RGB output right now, but plugging the cable directly into my TV works fine.

    Any idea what could be the cause of this?


    The NTSC PSOne should sync without any problem, watch the red led, if it’s lit then the OSSC isn’t syncing to the console.
    It might be that the PSOne AV connector is slightly corroded and has some unwanted resistance which might affect the sync.
    Go into the Sync.opt menu and try different LPF settings (off), if that doesn’t help try raising the “Analog sync Vth” setting.

    Sometime too much LPF may worsen the detection of the sync when the Vth is set lower than the sync signal.
    A proper strong sync should drop to near 0v while a weak or noisy sync will remain above 0v or closer to the 300mV mark in the worst cases.
    Another overlooked thing that can cause interference of sync is ground noise or buzz from the power supply, which as a result will never have a flat-line (quiet) references for the sync but spiky noise.
    So going too low or high with Vth may pick up some power supply noise, LPF helps with that.



    A noisy sync may look something like that (over exaggeration):
    * You want Vth to be in the green (default 123mV), between signal and noise floor (reds).
    noisy sync

    Yellow = Noisy
    Cyan = Clean
    sync 2


    Thanks for your detailed explanation.

    I played around with the sync settings a moment ago, but I it feels like it’s down to total luck
    whether the setting changes actually do something which is really irritating.

    For example just now the OSSC only managed to sync when I set the Analog sync Vth to 56mV (everything als resulted in permanent no sync), but even then it dropped out every 30 seconds or so and a restart of the console often lead to a total sync loss no matter the setting.

    Even if I manage to get it synced it never lasts long and the same settings suddenly don’t work anymore.


    What firmware?
    Do you have any other VGA or RGBS console or computer to negate the possibility that the OSSC or Cable are faulty?

    Try disconnecting the HDMI and see if it syncs to the console.
    If it does, try connecting the OSSC to a different power supply and a different outlet further away from the TV or console.



    Disconnecting the HDMI and using a different power outlet for the psone made no difference. I should be able to get my hands on a Gamecube RGB cable sometimes next week hopefully.
    I connected a Wii and a PSPgo over the AV2 though and both synced immediately.

    I also stumbled upon this thread earlier today:
    His observations are pretty similar to mine, are you definitely sure that the OSSC should work with a PSone? (the slim model)


    A friend of mine lend me some of his equipment yesterday, I just wanted to give a small update.

    PSone with different RGB cable-> same result
    GameCube with an RGB cable-> worked fine, so the OSSC doesn’t seem to be defective
    Connecting my PSone via a Framemeister-> same problem as the ossc with default settings (sound without picture), but increasing the sync level to around 25 fixed all issues.
    I get a perfectly stable image with these settings and the video output of my PSone seems to be ok according to the framemeister (59.82hz)

    I wonder if this affects all PSone units with the OSSC or if it’s just mine, but I guess I just have to use something different for this console.


    I have absolutely no problem syncing my PSOne to any screen.

    Try fiddling with “Analog sync LPF”, “Analog sync Vth” and “Vsync threshold”, I am sure you will find a setting that syncs.
    Usually lowering analog sync vth to 56-67mV works for me with troublesome consoles or ‘sync-on-luma’ cables.

    I did notice that having shared ground (through video cables) to the OSSC and my CRT, resulting in lower quality (noisier) sync signal and the default vth of 123mV loses sync.
    Unplugging the CRT from the main power and suddenly the Console+OSSC syncs with vth 123mV.

    Again, some sync problems are from noisy power supply or interconnected equipment.
    Try disconnecting all other devices from the OSSC (including HDMI) and leave only the console and OSSC.
    Did you try to change your PSOne power supply?

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