shmups.system11.org

Shmups Forum
 
* FAQ    * Search
 * Register  * Login 
It is currently Thu Aug 17, 2017 3:37 pm View unanswered posts
View active topics



Post new topic Reply to topic  [ 4 posts ] 
Author Message
 Post subject: Extron RGB - BNC to SCART wiring?
PostPosted: Sun Aug 13, 2017 5:58 pm 


User avatar

Joined: 09 Apr 2014
Posts: 151
Location: UK
Hello, I'm having some trouble with a BNC to Scart cable. Originally wired for Scart to BNC input (for say a PVM) but I'm trying to wire it for Extron RGB use so I can get it outputting to a Euro Scart TV.

Chain: 15khz Console/Mame PC > SyncStrike > Extron RGB 203 - RGBS > BNC to Scart > TV.

This is how the cable is currently wired. Originally the Yellow Sync cable was wired to pin 19 but I think it should be on 20 so I moved it. (There are no caps on any of the wires)
Image

When attached to a TV I don't get a picture but get some very weird black and white interference or just a blank screen, seemed like TV was struggling so I didn't test it more than a few seconds. The Extron shows a 15khz input on the display (testing with an RGB n64). Could it be that it's missing a 220 cap or maybe because there's no voltage on the 8/16 pins it's not going to work? Any help would be appreciated. TV is a Sony KV 21X5U if that helps.


Top
 Offline Profile  
 
 Post subject: Re: Extron RGB - BNC to SCART wiring?
PostPosted: Sun Aug 13, 2017 6:02 pm 


User avatar

Joined: 06 Mar 2006
Posts: 10504
Location: Germany
Is your TV in RGB mode ? Most TVs with Scart need a switching voltage to be present on pin 16 to enable RGB mode. Sounds like yours might be in composite mode instead. You don't need pin 8.

You can use a 1.5V AAA battery between pin 16 and ground.

And you need to move the audio pins from 1/3 to 2/6. And make sure pin 18 is grounded.


Top
 Offline Profile  
 
 Post subject: Re: Extron RGB - BNC to SCART wiring?
PostPosted: Sun Aug 13, 2017 6:41 pm 


User avatar

Joined: 09 Apr 2014
Posts: 151
Location: UK
Thanks for the info, Fudoh!

I thought switching to AV1 on the tv would automatically enable RGB but I guess that's wrong. Just retested it with a grounded pin18 and I can now see a very faint black and white image so you're right about it being in composite mode. Oh, that's interesting about the battery! I'll give it a try. Appreciate the help.


Top
 Offline Profile  
 
 Post subject: Re: Extron RGB - BNC to SCART wiring?
PostPosted: Wed Aug 16, 2017 1:18 pm 



Joined: 06 Oct 2012
Posts: 931
Its like Sync is missing Ground. if it is you get what your describing. My first RGB nes i built with the playchoice ppu, i didnt think you needed to hook up the sync ground. thought that one of the other grounds would take care of it. And I was getting
the same thing on my tv.

Check your grounds make sure they all have continuity.


Top
 Offline Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 4 posts ] 

All times are UTC


Who is online

Users browsing this forum: andykara2003, Bing [Bot], Carpetman, doonut, GeneraLight, hyne, kel, Kez, Triple Lei, ZellSF and 25 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum

Search for:
Jump to:  
Space Pilot 3K template by Jakob Persson
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group