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PostPosted: Tue Sep 03, 2013 12:56 pm 
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Joined: Sun Dec 02, 2012 8:17 am
Posts: 483
Location: East Texas
http://www.youtube.com/watch?v=IJP-OvE6KBY

I'm banging my head on this one.....

Here's some back ground:
I own roughly 70 consoles ( work related -- all snes first versions sns-001)
About 65% are "RGB" where I make a pcb that connects a scart cable to the AV port. The red/green/blue all have 220uF caps in series. The sync is stripped from CV with the 1881 chip. And I can connect my consoles this way to a rgb arcade monitor and some LCD monitors too. This method works perfect.

The other 35% of these consoles are what I call "non-RGB" in that I can't get a rgb picture out of it using the above method.
I made a video (link above) showing that the rgb is making it to the monitor (arcade CRT rgb monitor) but it appears that the sync is wrong. This is where I don't know what to do or why the sync isn't making it to the monitor or???? The few consoles that I opened up have 2 different encoder chips... The non-rgb uses the BA6592F and the rgb uses the S-ENC chip.
Does the BA6592 chip not output C-video? Or does the sync need to be amplified? I really don't understand why they would be different.

My scart to AV port is wired using this as guide: http://members.optusnet.com.au/eviltim/ ... t.htm#snes
My sync stripper is same as here : http://www.mmmonkey.co.uk/composite-syn ... er-lm1881/
My cable is this: http://www.ebay.com/itm/ws/eBayISAPI.dl ... 0948949594
There are other details in the video.

Again, this method works great for about 65% of the console... Why it doesn't on the other is my mystery. They all have C-video and rgb. So what's the difference?

Thanks for any help.


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PostPosted: Tue Sep 03, 2013 3:52 pm 
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Joined: Sun Jan 06, 2013 9:56 pm
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Do the RGB lines have the 75ohm resistors as well? I know my Genesis had issues with my monitor without the resistors on the RGB lines.


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PostPosted: Tue Sep 03, 2013 7:07 pm 
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Joined: Sun Dec 02, 2012 8:17 am
Posts: 483
Location: East Texas
I tried tieing them high and low. No change other than brightness of the rgb (which was still out of sync)


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PostPosted: Wed Sep 04, 2013 3:23 pm 
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Joined: Mon Jul 02, 2012 7:46 am
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Markfrizb wrote:
I tried tieing them high and low. No change other than brightness of the rgb (which was still out of sync)

I think he meant series resistors


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PostPosted: Wed Sep 04, 2013 4:18 pm 
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Joined: Sun Dec 02, 2012 8:17 am
Posts: 483
Location: East Texas
I did not try a resistor in series (the scart chart showed resistors tied to ground for the PAL consoles but not for a NTSC).
But I don't think it's the colors as the colors are showing up on the monitor but not in sync.


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PostPosted: Wed Sep 04, 2013 5:54 pm 
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Joined: Sun Jan 06, 2013 9:56 pm
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qwertymodo wrote:
Markfrizb wrote:
I tried tieing them high and low. No change other than brightness of the rgb (which was still out of sync)

I think he meant series resistors



I did mean in series. Also try a 220uf caps in series on your sync line, this was part of my Genesis fix.


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PostPosted: Wed Sep 04, 2013 5:57 pm 
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Joined: Sun Dec 02, 2012 8:17 am
Posts: 483
Location: East Texas
I'll give it a try. Thanks!


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