No Picture on AV1 on Optoma Beamer with Denon Reciver

[warpstarpilot]

Hello,
I recently purchased the Open Source Scan Converter (OSSC) V1.8 from you; AV2 and AV3 are working very well.
However, I am not getting a picture via the SCART input only sound for a fraction of a second every now and then.
On the Display of the device Shows in the upper Right changing p numbers and on lower left changeing Hz numbers.
I encounter this problem with all the consoles in my collection (Sega, Nintendo, Sony, Atari, and a few others).
Everything works perfectly on my CRT TV.
I have the device connected to my Optoma UHZ55 projector via a Denon AVR-X2800H receiver.
Previously, I used a cheap SCART-to-HDMI converter that worked without any issues.
I decided on the Open Source Scan Converter (OSSC) V1.8 because it is supposed to produce a better image and the scanlines enhance the picture; plus, it allows me to save two HDMI inputs.

I hope you can help me with this.

Best regards,
Brian Böhme

• This topic was modified 3 weeks, 4 days ago by BuckoA51. Reason: wrong forum

[BuckoA51]

Are your consoles all RGB capable and your SCART cables properly wired for RGB?

[warpstarpilot]

Yes, all consoles are  RGB capable and properly wired with SCART cables for RGB

[BuckoA51]

Any kind of SCART switch between your consoles and the OSSC?

[warpstarpilot]

Yes, because I don’t want to constantly unplug and replug cables when I want to use a different console.

Furthermore, it’s very inconvenient since the cabling and switches are integrated into the cabinet.

 

[BuckoA51]

What’s the make and model of the SCART switch?

[warpstarpilot]

Since the SCART connectors kept coming loose, I converted them to SUB-D (using screw-locking connectors); for switching, I use mechanical switches from Inline.

When I connect my Sega Mega Drive 2 directly via my SUB-D to SCART adapter cable, the picture and sound appear briefly.

Does the OSSC require a higher signal level than a cheap device?

[BuckoA51]

Not usually, no. Do you have a direct link to that switch? What kind of SCART to d-sub converter do you use?

So what is the entire video chain, including all cables, converters etc, from any one console to the OSSC ?

 

[warpstarpilot]

I modified every console’s RGB cable to use a 9-pin D-Sub connector and built an adapter from 9-pin D-Sub to SCART.

The following signals are used:
Audio Right
Audio Left
RGB Blue
RGB Green
RGB Red
Aspect Ratio
AV/RGB Switching
AV Signal
Ground

After changing the following settings with the help of Google AI, I had a stable image for a few minutes (using the switcher), but then lost the signal completely.
Under sync options:
Analog sync Vth 157mV
Hsync tolerance 4.00ms

I am using the following switcher.

https://www.ebay.de/itm/185910405682?_skw=InLine+Seriell-Umschalter+manuell+4-fach%2C+RS232%2C+9-polig+Sub-D&epid=18051827968&itmmeta=01KY7C6X71YYWA44PJ9TMRX6DW&hash=item2b491faa32:g:Jm0AAOSwDldkbM34&itmprp=enc%3AAQALAAABIGfYFPkwiKCW4ZNSs2u11xD%2Bp%2FbHy2VPXwWVN5cnuJCKiL58UjkuVb2doSnItY9hJfxIUWzM%2FwYJo3siGNQ0a%2BzvJ3nabbePT95qjmea4VQbPRXfpPNtkWSno7l4lvO9RzZ9heztliFqNdPz6z9AxjodAZqNyku%2BTbXrw4mlXWgKcwmrDDpCYVGEAG9cY2VzwNVaFAj4rqUZGNdvdO%2BZYrhNxWz2i9zt%2FBKAEN%2FWgb2MJfaFQfqRtMvCcty1hEEeGFebFc5mZS753NBaVHfnCsvaE31gkR7oMaJkHctKuYDmjMxBPIO01I7jwiwvkHv%2BxmxqELFURdzWkXSWNIbNiHbtUil4N8HkzhTPKXS1l8TZMvBGidsj2rdw5FvBDO%2B0WA%3D%3D%7Ctkp%3ABk9SR-TTm-zxZw

[BuckoA51]

Hmm, how are you pulling sync from the consoles, if you’re using csync have you attenuated the output correctly? Aspect ratio and AV RGB switching would be ignored by the OSSC.

[warpstarpilot]

If I’m not mistaken, sync is transmitted via SCART pin 20, which is also used for composite video (AV).

Could the sync signal be too weak?
How could I amplify it?

[warpstarpilot]

Would an LM1881 (sync stripper) help?

[BuckoA51]

Sync is indeed sent to pin 20 on the SCART end, but can be taken either from composite video or cysnc output on many consoles. A sync stripper should not be needed with the OSSC though proper attenuation is required when using CSYNC.

My guess would be the VGA switch not having enough bandwidth for the composite video signal on that particular pin as it is not designed for it, but, if your cheaper adapter works that seems to put an end to that theory.

It’s unlikely but, at this point can you find a regular SCART cable and try that with your OSSC just to make sure there isn’t a fault with the SCART input?

[marqs]

Is the linked switch perhaps using logic switches instead of analog multiplexers? Or maybe it’s mechanical if there is no power supply. If you have original AV cables for some of the consoles and RCA-scart adapter, you can try connecting that to AV1 and see if stable sync is at detected (picture is then blank).

[warpstarpilot]

I’ve only just had the chance to do some further testing.
I’m using a VGA switch on the VGA input, with a Dreamcast and an analog tuner connected; both work flawlessly.
For the SCART input, I’m using a 9-pin D-Sub switcher. The switches are purely mechanical.
Since I only have one RGB cable for the Master System, that was the only one I could test with; the picture and sound are good, but it doesn’t always work.
After soldering the LM1881 into my 9-pin D-Sub adapter, the digits on the display remain stable, but I have neither picture nor sound, and the LED at the bottom right is lit up red.

If the switchers happen to be the problem, which ones would you recommend for connecting 11 RGB-capable consoles?
I also plan to expand my collection significantly.

 

• This reply was modified 2 weeks, 4 days ago by warpstarpilot.

[Author]

Posts