Problems with SNES and Zenith CD15MNTC1

[chrisadd]

I apologize if there is already a topic already addressing this.  I've been searching for hours and I haven't yet found a solution.  I recently purchased a Zenith CD15MNTC1 for an RGB connection to my Super Nintendo (this is the RGB monitor from the Super Nintendo kiosks in stores), but it did not come with the necessary cables.  It has a DB9 connector on the back and I found a website which gave a pinout for that connector:

http://www.electronicspoint.com/lf-schematics-c1991-zenith-cd15mntc1-color-monitor-flat-tension-mask-t102455.html

pin 1: ground
pin 3,4,5: RGB inputs
pin 8: composite input (video + sync)
other pins not connected inside.

The monitor came with a Japanese RGB-21 cable for the Super Nintendo and inside the cable, there are 220uf capacitors on the RGB wires.  I found the RGB-21 pinout on this site here:
http://gamesx.com/wiki/doku.php?id=av:japanese_rgb-21

So, then I wired the following:

Ground: DB9 pin 1 to RGB-21 pin 14
Red: DB9 pin 3 to RGB-21 pin 15
Red: DB9 pin 4 to RGB-21 pin 19
Blue: DB9 pin 5 to RGB-21 pin 20
Sync: DB9 pin 8 to RGB-21 pin 9

I also wired audio from the RGB-21 to two RCA cables and the audio works fine.  However, the picture is very distorted:

http://i.imgur.com/b2JeO.jpg

It almost looks like a negative of the normal picture and there are wavy distortions throughout.  Any ideas what I did wrong?  I'd really appreciate it if someone could give me some advice.

Thanks!

[NFG]

First thing I'd check is your grounds, make sure you're connecting ALL grounds on both ends, you never know which one the machine is using, or if it'll freak out if it's missing any.

The way you're getting the leading edge of each colour but nothing after that suggests to me that you should have a look at the capacitors.  Did you leave them in there?  If so, try removing them.  If you removed them, try putting them back (positive side towards the console).

[chrisadd]

I am connecting the "audio shield" to the jacket of the RCA plug and the ground of the monitor to the "ground" from the RGB-21... I think I need to do a bit more reading because I'm not sure what you mean by connect ALL grounds on both ends.  As for the capacitors, yes I did leave them in.  I will try bypassing them to see what happens.  Thanks for the tips!

[NFG]

Ah sorry, I was thinking of the RGB21 when I wrote that.  It has many additional grounds. 

Your 9pin connector may have a metal shell around the other 9 pins.  Is it also grounded?  Probably not critical, but it's a good habit to get into.

[chrisadd]

Well, I finally found the board to go from RGB-21 to this monitor.  I was never able to get it working on my own and after looking at the board, it was way too complicated for an electronics novice like me.  Anyway, I hooked it up and it works!  Here are some pics of the board in case someone else needs info on this.

http://imgur.com/a/2uPh6

By the way, I hooked up my Genesis with a scart cable and scart to RGB-21 converter and it also works with this setup!