Extron setup/component/BVM - Sync loss on flashing images

[Turom]

Hi there,

I have been using my setup for a while now and I notice on component sources (PS2/NGC/Wii/PS3) when the image goes like all white/flashes I loose sync for ~1s occasionally. It's not 100% of the time but it's frequent enough to be distracting. I'm looking for a way to eliminate this issue.

Here's the chain:

Consoles => Extron Crosspoint 300 => Extron RGB 192 interface => Extron Crosspoint 300 => Multiple BVM-D monitors

More info:
- I use HD Retrovision cables/OG Wii/NGC component cables, NTSC signals
- 75Ω switches are ON on the Crosspoint even though I believe it does 75Ω anyway whatever the switch position
- If I connect the component sources directly to the BVM after the Crosspoint I can't get sync even with the SYNC button on the BVM remote, colors are correct but no sync, image is waving
- I make a loop with the Crosspoint so all the monitors benefit from the Interface DDSP
- Activating DDSP on the RGB Interface is the only way to have sync on component
- SERR on the Interface helps on the Dreamcast/XBox360 to get better sync but does nothing on component sources, I have to deactivate it for some Saturn games
- SoG switch on the Interface does nothing for component sources
- I saw it happen on 480i, 480p, 720p
- It happens on several monitors, all BVM D series
- When it happens, generally after a full sudden white image, the screen goes blank/dark like a few frames then when the image comes back the sync is gone (like when DDSP is disabled or when I don't use the interface) and then the sync comes back after ~1s

Any idea where I should look to tackle this problem? Is it normal that I don't have sync without DDSP on those monitors? Could it be the interface that is a bit weak and I should try another model? Maybe there's something I missed.

[fernan1234]

generally after a full sudden white image, the screen goes blank/dark like a few frames then when the image comes back the sync is gone

This is typical with hobby products/setups where the voltage levels on the video and/or sync lines are incorrect. If you look this kind of thing up you'll see it was very common with the output from older superguns and such.

What I don't understand is why your component consoles/cables don't work with your BVMs directly connected. Those BVMs should be perfectly compatible with YPbPr inputs when component is set to YPbPr and sync set to internal on the monitors.

But anyway, what happens when you bypass the Crosspoint altogether and simply go console -> interface -> monitor?

[Turom]

Thanks for your reply, thanks to you I think I nailed down the issue, it's a bit dumb but also a bit tricky:

- When you open the INPUT CONFIGURATION menu, pressing the SYNC button doesn't change the value displayed on screen so for some reason I though it was the wrong button, I wasn't using it correctly and didn't realize the front button shortcuts are not the same set of settings. I feel dumb about this but I though it was "working" without it because :
- When SYNC is set to EXT when going through the interface it's the interface itself that does the sync management and that was where the issue was. While using the interface, switching SYNC INT or EXT seem to do nothing because both modes display correctly. I believe I had bad luck having the three monitors set to EXT while doing my tests without interface.
- I tried setting the SYNC mode correctly to INT and I could use the component sources directly into the monitors and even when going through the interface with no more desync happening because the monitor ignores the sync line completely

Looks like the interface had trouble keeping the sync sable with component and deliver it consistently to the monitor, and when the monitor handles it itself ignoring the sync line there's no problem at all.

Thanks for reading and pointing me to the right direction

[fernan1234]

Good to hear you figured it out. You really should not need the RGB interface at all for YPbPr sources. For hobby purposes, the interface is only really useful either to combine sync from RGBHV (VGA) sources, to fix bending/flagging on the top of the screen from certain sources (SERR switch) or compatibility with HD sources (DDSP), and in some cases to have control of picture centering (though DDSP needs to be off for that to be enabled).

[Syntax]

I cant think of a Component to RGB convertor that doesn't lose sync on bright scenes. Its just what happens when they clip.

For this reason I steer clear of that conversion and stick to RGB to Component instead.