Help: Saturn NTSC RGB Problems

[Shelcoof]

Hi Folks

I've done a search looking for any articles that may help me out and I couldn't find any so I hope no one gets upset.

A friend had suggested I ask for help in this forum regarding Saturn RGC Scart Cables.  I've been trying for months now to get my NTSC Model 1 Saturn working with RGB cables I've bought over the span of 3 months.

So far nothing I've bought seems to be working.  Just to confirm though, I have been able to get my Saturn working with a friends Custom Saturn RGB cables and they worked great.  Unfortunately for me I'm sure he's not willing to let them go.

I've bougth Cables from Play-Asia which output RGB very well but just has problems keeping the image stable.  They pretty much are unusable.  I just got a pair of Official Pal Saturn RGB cables and all they output at the moment for me is composite.

I've done some reading and I'm guessing it has something to do with the Resister or the voltage but thats about it.  I don't know how to
fix the problem at all.  I've included here pictures of both cables.

http://img35.imageshack.us/gal.php?g=palcables1.jpg

If some one could tell me or point me to a guide that would be amazing.  Yes I can solder btw.

I dunno
Please help a retro gamer in need ~_~.

Thanks
Shelcoof

[albino_vulpix]

It looks to me that with both cables, there is no connection for +5v the TV needs to switch into RGB mode. The second cable shows no wires on the SCART end connected to pins 8 or 16, and though the first cable shows a resistor bridging these two pins, the pin in the 10 pin din plug that's supposed to carry +5v is missing.

It looks like you can fix up the playasia cable, since it has all the pins wired. http://members.optusnet.com.au/eviltim/gamescart/gamescart.htm#saturn

[Shelcoof]

Hi albino

Thanks for replying.  The Play Asia Cables don't work for some reason.  I tore out the yellow wire and I get steady composite.  If I re-connect the yellow wire I'll get RGB that isn't steady.  I'm using a converter to play it on my HDTV.

This enables me to upscale the signal to 720p.  This HDBox I have works for all other RGB signals except for the Saturn.

What happens is that the picture will appear then disapear and take a few seconds to show up again.  This happens randomly.  Its so bad that games become unplayable.

I'm hoping I can find information on modding my Pal cables to get it working.  The Pal cable is the one with the resister.

Thanks
Shelcoof

[albino_vulpix]

Looks like the yellow wire is the one that carries the +5v. Re-attach it to pin 8, then bridge pin 8 and 16 with a 100 - 180 ohm resistor and it should work.

[Shelcoof]

Hi Albino

Thanks for the step by step guide. 

So this was the problem all along?  There was no bridge between Pin 8 and 16.  The only thing that was there was Pin 16 connected and Pin 8 was left untouched.

I don't have a resister now but I'll pick one up this week and fix it up by this weekend.

btw I have an NTSC Console I hope this method works.

Also about the official Pal Cables... is there a possibility of fixing those?

Thanks again for the help.  I'm crossing my fingers this time.

Shelcoof

[Midori]

If the PAL cable is indeed missing the 5V pin in the mini-din plug then that is close to impossible to fix without changing the whole mini-din plug. Quite odd that the 5V would be missing, my PAL saturn RGB cables has got it.

[Shelcoof]

I asked the seller if it outputed RGB he said yes on Pal televisions.

So what your telling me is that these cables will not output RGB unless I modify the mini-din plug?

Thanks for replying.
Shelcoof

[Midori]

Well technically the cable does output RGB, just that most screens require a 5V line to tell them that it is RGB, otherwise they assume it is composite. So while the RGB signal is available in the cable there is nothing that tells your screen that it is a RGB signal and it assumes it is composite :-)

You could of course connect a 5V source from somewhere else and route it into the cable, that would work.

So there are of course ways to solve the problem, but none of the available are easy or preferable :-)

[Shelcoof]

well I'm stumped.. it didn't work.  I used both 100 and 180 and no go

I'm sure I wired it correctly as well.

sigh

[albino_vulpix]

Strage that it doesn't work. If you have a camera upload a photo of your work. Also, if you have a multimeter check the continuity of the wires, and check that the pins all line up as shown in the diagram in my first post.

[Shelcoof]

Hey Albino

It looks just like the Pal Cables I have in the picture.  I'm sure I followed the diagram exactly and I used the Pal cables also as a guide.

I'm running into the same problems I had before with the cable.  I get a nice solid picture for a few seconds then it disapears for like 2-3 seonds then appears again.  This happens randomly all the time.  I've used both resisters and they both have the same effect.

I even went to the extent to rip up my 3rd cable to use the mini din that didn't work.  So I then cut up my Pal cable and used my Play-Asia Mini-Din with my Pal Scart Lead.  This resulted with composite signal only. So I changed the resister and then it worked but suffered the same problem earlier with the display going off for a few seconds then returning.

So I have no clue what else to do.

[albino_vulpix]

So this is whats going on: without applying the SCART voltages (pins 8 and 16), you get a perfect composite signal, but with the voltage applied, it randomly disappears? You might want to look at insulating the resistor with some tape. If that's not it, try another SCART cable that's known to work on that TV.

[Shelcoof]

Hi Albino

Yes Smooth Composite Signal without resister installed.
Excellent RGB with the resister but... disappears for a few seconds then appears again randomly for various amounts of time.

OK I'll use some electrical tape on the resister.

If that doesn't work you suggest I cut up another pair of cables and try it out? (I have a pair of Dreamcast RGB cables I could use but I dunno cables are pretty expensive)

Thanks again for replying

[albino_vulpix]

Do these Dreamcast cables work on the TV you're trying the Saturn cable on?

Either way, I suggest you don't cut anything up if it works.

[Shelcoof]

All my other RGB cables I own work except for the Saturn RGB cables.  I use my cables on a converter that upscales the signal to 720p.  My HDTV does not accept any sort of Scart cables, I have to pass the signal through converter and output it to either HDMI or Component on my HDTV.

The Dreamcast cable is only used to play F355 Challenge in Widescreen mode.  If I use the VGA adapter I'm unable to enable widescreen mode.  So the Dreamcast RGB cable is only used for one game.  Luckily for me though I've upgraded to using the PS2 and the Forcefeedback Racing Wheel for for F355 Challenge.

So I guess I can sacrifice the Dreamcast RGB cable if I have to.

[viletim]

Shelcoof,

This is a problem with the official Saturn SCART cable. The resistor value they chose results in a RGB status voltage which is right at the lower limit.

Did you try to simply change the value of this resistor? (I'm referring to the one between pins 8 and 16 in palcable4.jpg) 180 ohms is the best but anything between 100 and 200 ohms is ok. The original value is 270 ohms which is far too high.

[Shelcoof]

hi viletim

Yes I have replaced the original resister with a 180 and 100 ohm resister and still no luck.  I keep getting a picture that goes out randomly.

I believe the converter I own may contribute to this problem.  It must be very picky with the signal.  Any interference and it would go out and take a few seconds to display the picture again.  I'm sure it takes time to process the signal before it upscales it.

If this was an ordinary HDTV that accepted Scart cables I'm sure the image would get distorted or slightly glitch for a few milliseconds rather than a few seconds.

I most likely will need a pair of high quality cables like the one my friend had.

[albino_vulpix]

Oh it's running through an external converter? I'd say that's it then. Some modern display devices just won't display signals from old machines. My projector simply refuses to show colour when I plug my Master System into to, using either composite or s-video.

[Shelcoof]

Hey albino

I don't think the converter is the problem.  I've been able to get steady RGB on the converter with everything else including my saturn.  I used a buddy's Saturn RGB cable and it worked perfectly fine no problems what so ever.

The picture was solid and stable with no hick-ups like the cables I own.  Though the working cable I used was a custom made cable.  I've contacted the seller who produced those cables and no reply back for over a month now.

[albino_vulpix]

Is your converter happy to display a picture when one of the RGB colour lines is disconnected? I'm thinking it's a loose wire, but not a ground due to the steady composite.

[Shelcoof]

I'm not sure I'll take a look at it when I get home

Edit:  I snipped a wire while it was on and it still displays the image, however though I see a tan of red.

[albino_vulpix]

Maybe the converter uses seperate ground connections for composite and RGB. COnnect all the ground pins in the SCART plug together.

Yeah I'm running out of ideas.

[Shelcoof]

I give up

Thanks for all the help though.

I think I'm gonna stick with S-Video and my Standard TV.

It still looks super sexy with S-Videon the Standard TV though...