No Picture on AV1 on Optoma Beamer with Denon Reciver

[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 3 weeks, 5 days ago by warpstarpilot.

[marqs]

LM1881 typically just adds more issues than it solves unless connected exactly right. It’s futile to blame the switch without knowing its internals, but if you’ve tested various consoles through it without success then the issue can really be on the switch/connection or then the OSSC input is faulty.

Sometimes these kind of switches switch only a subset of lines and just connect others together. Maybe it’s a good idea to open it and check that all 9 lines are truly switched.

[warpstarpilot]

I removed the LM1881 and ran further tests.
I also used my old SCART switchers during this process.
The OSSC only operates stably when I connect the console directly; as it stands, the OSSC is unusable for me.
Is there a way to boost the sync signal?
Or is the OSSC defective?

If there is no solution, I will be forced to return the device at your expense.

[marqs]

It’s hard to count out the possibility of that OSSC being defective, but if it works with direct connection but not through a dumb mechanical switch, then at least I’d open and check the switch if it was my setup. Have seen enough bad scart switchers in my lifetime that only switch subset of lines.

[warpstarpilot]

As previously mentioned, everything works perfectly with my CRT TV and the cheap SCART-to-HDMI converter (which supports composite video, S-Video, and RGB).
I tested the switchers for continuity and measured 0 ohms of resistance (this applies to both the 9-pin D-Sub units and the SCART switchers that allow toggling between RGB and composite/S-Video).
The OSSC is the only device with which I cannot get a stable image, so the issue must lie there.
Would an update help?
Or is the OSSC hardware simply poor quality?

 

[marqs]

0 ohms into selected line and infinite resistance to inactive inputs? The frontend chip is a graphics digitizer that is not designed for sources with bad sync quality which could explain difference to CRT or generic video converters. That said, it has been tested with various powered and unpowered switches without issues.

[warpstarpilot]

I think I managed to solve the problem,apparently, the cable on my SCART-to-D-Sub adapter was faulty.

 

The LED at the bottom right is now also glowing a steady green.

 

At least the Mega Drive seems to be working now.

I’ll test the rest once I’ve got everything connected again.

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