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Issue with picture using Scart to Component Converter w/SNES

Posted: Tue Mar 22, 2011 6:41 pm
by Amplibax
I finally got around to ordering Scart to Component Converter. I got a CVS2087 which is basically a CSY-2100 clone. I plan on getting all my old consoles on scart eventually. The converter arrived today and to my surprise it actually worked (for the most part) on both of my LCD tvs. I was expecting to get unsupported video mode on both. It works perfectly on my 24 inch Toshiba, but my my larger 40 inch Sharp I am getting some weird distortion at the top of the screen whenever a games displaying light shades of colors. Some pictures will show this best I'm sure.

Here a few to show how distortion looks on my 40 inch Sharp:

Image
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Now on the same tv, it looks fine here because the colors are all dark:

Image

Now just for fun here is a comparison of the quality difference between AV and RGB on my 24 Inch Toshiba:

AV:

Image
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RGB:

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This is the RGB cable I bought for my SNES

http://cgi.ebay.ca/ws/eBayISAPI.dll?Vie ... 0455191841

They claim it is fully wired and should work so any ideas on how I can get this working right on my big tv?

Re: Issue with picture using Scart to Component Converter w/SNES

Posted: Wed Mar 23, 2011 4:58 am
by Anapan
I don't have a solution to your problem, but I can tell you my experience and stuff I've read about it.

My CSY-2100 does the same thing on my CRT TV, tho not so extreme. It mostly happens on SNES games (Mario World & Mario Paint come to mind), tho I think my XBOX1 has done it as well.

What makes me suspect it's probably not completely the transcoder's fault is the same thing happens on my 1084 Amiga monitor hooked up directly through SCART if I push some buttons on it. There's a switch on the front of the monitor labeled "CVBS/RGB" that corrects/breakes the the interference/warping band at the top (the signal from the cable it uses is RGB regardless of the button's position tho CVBS means Composite I think). There's another button on the back labeled "VCR" that makes the interference much worse to the point of showing a dark bar at the worst affected part if the front button is switched off or only a slight jitter at the very top when left alone (in any case, the 2 of them set correctly completely eliminate the problem).
Just like what's happening on your display, it only happens on a select few games that have near-full-width really bright colors and it happens at the exact same spot.

Fudoh mentions the same problem in the X-RGB3 section of his site http://retrogaming.hazard-city.de/
In the X-RGB3, the "NTSC AFC" option can correct the problem (AFC means Automatic Frequency Control). He's very knowledgeable about this stuff so it wouldn't hurt to ask him.

In another forum post I found on Google (lost the link), some guy claimed that the capacitors in the RGB cable at the SCART end should be replaced with a different type (the saucer-shaped ones instead of the cylindrical ones) to correct the problem. (also I can't remember for sure but he might've suggested trying a different capacity, too). There were no followup posts and I haven't tried it so I can't comment on it's effectiveness. I just found a bookmark I made with some insight about the capacitance's function that suggests putting higher capacity ones might fix the problem. Link here.

In yet another forum post I googled up, some guy suggested opening the CYP-2100 up while it was running, marking the original potentiometer positions with a felt marker, and messing around with them. I think he had a picture on which ones to tweak, tho my memory's a bit fuzzy about that. Probably a bad idea anyway...

When looking up a solution some more, there was mention of some cables being wired up to use the composite pin for a sync signal, or having the sync signal wired to the wrong pin. Switching the composite sync to the correct pin might fix it.

Edit:
I'm kinda bored so I decided to Google it some more and apparently SNES's PAL and NTSC RGB output is different. It could be that we just have the wrong stuff in the cable...
http://members.optusnet.com.au/eviltim/gamescart/gamescart.htm
http://www.sega-16.com/forum/archive/index.php/t-4042.html

Re: Issue with picture using Scart to Component Converter w/SNES

Posted: Wed Mar 23, 2011 10:41 am
by Amplibax
Hmm I'm surprised you had the same issue on a CRT. I was half expecting I would need a CRT in order to even get ANY picture with this device. Thanks for your investigating this. I guess my options are going to be to either modify the cable or CVS2087 or try out a new cable.

I've read around various pleases that the NTSC SNES uses the same scart cable as the PAL Gamecube. (it even says that in the eBay auction) So I think I do have the right cable.

I remember reading so many threads with issues like these online, but I just can't find any of them anymore. I opened up the cable and their are 3 100uF caps which I assume each go to R G and B. If anyone can find anything that specifies exactly which value I should exchange these caps to please let me know! Otherwise I may go ahead and order another cable possibly from this site.

http://www.robwebb1.plus.com/snes/snes_hard.htm

I do also have a Genesis scart cable on the way so I'll update when that arrives too.

Re: Issue with picture using Scart to Component Converter w/SNES

Posted: Thu Mar 24, 2011 12:42 am
by modsbox
The capacitors in the cable on the RGB lines should be 220uf each, not 100uf. That very likely could be causing the problem.

I bought my NTSC SNES RGB cable from play-asia.com , you might just grab one from them. Works great with my CSY-2100 clone.

Here's the link to the 220uf info on gamesx.com:

http://gamesx.com/wiki/doku.php?id=av:nintendomultiav

Hope this helps!

Re: Issue with picture using Scart to Component Converter w/SNES

Posted: Thu Mar 24, 2011 1:55 am
by Anapan
I don't remember where I got my cable, tho if I look through some old emails I should be able to find out. I just opened my SNES cable and it has 4 220uf electrolytic capacitors. I don't have time now to identify the pins they're on, but I'll fully investigate it tomorrow. Thanks for the replies. I'm sure we can get this figured out. I'm gonna find the extraneous capacitor and eliminate it to see what happens.
I've had no issues with my Genesis cable. The picture is so much improved that I could never imagine going back to Composite on the system.

Re: Issue with picture using Scart to Component Converter w/SNES

Posted: Fri Mar 25, 2011 12:24 pm
by Amplibax
Thanks for the responses guys. I may go ahead and get that one from Play-Asia. It's on sale right now and may very well cost less than the 3 caps + shipping to modify my current one. Does anyone have a recommendation on a scart switch box? I'm looking at a couple but none seem to mention if they are RGB compliant. Like these for example:

http://cgi.ebay.ca/Bush-3-SCART-1-SCART ... 3f086be886

http://cgi.ebay.ca/ws/eBayISAPI.dll?Vie ... 0201161729

I ideally would like to have one that has the scart cable that plugs into the scart-yuv converter attached to the device like with those two rather than having to buy a scart male to male cable. Should I assume any scart switch with all 21 pins is RGB compliant?

Re: Issue with picture using Scart to Component Converter w/SNES

Posted: Wed Mar 30, 2011 9:15 am
by Amplibax
Alirght so my Genesis cable arrived today and it worked perfect on both tvs! I opened it up and it had the 3 220uf caps on R G and B. I'm gonna go ahead and order the SNES scart cable from Play-Asia. Hopefully it will have the proper caps. Also ordered this scart switch which seems to be quite a good deal:

http://cgi.ebay.ca/ws/eBayISAPI.dll?Vie ... 0784806190

Re: Issue with picture using Scart to Component Converter w/

Posted: Mon Feb 04, 2013 4:56 pm
by kiario
I have the exact problem but on 3 CRT TV's 21"-29. But not on my 14" TV. PAL SNES. Any idea???

Re: Issue with picture using Scart to Component Converter w/

Posted: Mon Feb 04, 2013 5:03 pm
by Jamisonia
There are two SCART cables floating out there for Nintendo systems. NTSC SCART cables released in Japan have 100uf caps on each line in the cable. PAL SCART cables have 75 ohm resistors connected to ground on each line.

The only other difference is the NTSC consoles have a dedicated Composite Sync output pin. The PAL consoles do not. They instead have replaced that pin with 12V, and the PAL scart cables run the composite video output for sync.

Recently Ziggy modded his PAL SNES to put RGB jacks on the console and use RCA cables. He then put these through a professional RGB to YPbPr converter he found on eBay. He found the converter did not work until he tapped the composite sync pin from the video chip itself. I would start there. Maybe Ziggy will chime in with more info.

Re: Issue with picture using Scart to Component Converter w/

Posted: Mon Feb 04, 2013 6:16 pm
by theclaw
Some TVs are incompatible with 240p from component input. If all else fails, resolution could be the problem.