Unstable image JP Dreamcast & JP Megadrive JVC BMH2000PND

[theclaw]

Maybe the JVC doesn't accept composite as sync for RGB signals. In this case you would need a breakout cable with a stripper built into it. You would need to check with another JVC user to verify this.

Don't both consoles already output c-sync?

[Fudoh]

as he just proved by connecting them to the composite input, no.

[Crayfish]

The JVC monitors do (only) accept c-sync. Im running RGBS on this same model, a 14", 19" 0CG and a high end DTV set too.
Mainly it is the NEC display monitors that require a sync stripper, and they are pretty rare.

[theclaw]

as he just proved by connecting them to the composite input, no.

Then I'm confused. What is the separate sync pin Sega provided on the back of the console for?
I was lead to believe Megadrive and Dreamcast support rgb cables of either variety. With or without composite video.

[Fudoh]

Then I'm confused. What is the separate sync pin Sega provided on the back of the console for?
I was lead to believe Megadrive and Dreamcast support rgb cables of either variety. With or without composite video.

Ah, ok, I assumed you were connecting the sync breakout cable from your adapter to the composite input, but you used a genuine composite cable instead ?

Just try the same input using the actual signal from the breakout adapter to see if you get any image.

Did you try that GND bridge from the sync shielding to a ground pin from the coupler ?

[MK75]

So pleased right now.

I bought one of those multi input switchers. Enabled the RGB button, using a RGB cable for my JP MD and this is the result:

https://ibb.co/h6uHea

And likewise with the JP DC, obviously not VGA but a decent cable running from machine to the JVC...looks better then the composite (but it was nice to compare)

See below.

https://ibb.co/dVFOKa

https://ibb.co/g1G2Cv

Turns out it was the fem/fem block. The most simplest of explanations.

Thanks all

Much appreciated.

[Crayfish]

Looks great.
Next project is a unit / shelves so u can have your systems all set up and just flick between them with the switcher.

[AndehX]

Call me crazy but that scart to bnc breakout cable looks like it's expecting sync on pin 19 whereas sync is always wired on pin 20 in RGB cables. This would explain why the breakout cable has a male scart plug and not female. Looks to me like it's a bnc to scart cable....

Oh you fixed it. Nevermind lol

[blackhood1]

So pleased right now.

I bought one of those multi input switchers. Enabled the RGB button, using a RGB cable for my JP MD and this is the result:

https://ibb.co/h6uHea

And likewise with the JP DC, obviously not VGA but a decent cable running from machine to the JVC...looks better then the composite (but it was nice to compare)

See below.

https://ibb.co/dVFOKa

https://ibb.co/g1G2Cv


Turns out it was the fem/fem block. The most simplest of explanations.

Thanks all

Much appreciated.

Link is not opening in my browser i am using portable version of safari.