evietron

I hooked up the Ambery converter and it works flawlessly. No more cheap no-name boxes for me! Thanks Mr Robot, that was an awesome suggestion. I'm going to mount an S-video connector where the RF modulator is (I've already destroyed the thing), and then re-hook up the composite so I can use that as an option. Up until now I've been using a rewired composite RCA as luma and RF RCA as chroma. DrVenkman, I will try some test patterns once I get an SD solution on my machine. For now I am just using Missilie Command and the built in test.

Thanks Mr Robot, I think I'll try the Ambery converter. From the scope, the signal looks great. Up until now this converter box (Tendak) has worked on everything.

I hooked up a scope and discovered the "color burst" signal. That helped me configure the right values for R55 and the color pot. The inductor seems to be filtering AC voltage properly. So that pretty much leaves my converter box as the suspect. That, or the luma circuit is somehow out of phase with the chroma. Has anyone had good luck with RetroTink2X with an XE machine?

Unfortunately I don't own a CRT TV. I use a converter box that goes from composite or S-Video to HDMI. Is there a good guide for studying a chroma signal through a scope?

Attached schematics. I replaced the Q5 transistor and now get slightly more color bleed but it still is not stable at all. I just get flashes of various color on the screen. I'm picking up the color signal from the output of Q5 for the chroma output. I already replaced R55. So basically the only thing left is L5 and then the 5V power supply. One other question .. the video upgrade mentioned a tantalum capacitor between R78 and R79. I am using an electrolytic instead. Could this cause problems? (Although that is on the luma circuit which seems fine)... XEGS System Schematics.pdf

I got a pristine like-new XEGS off eBay, and the color doesn't work. I tried all kinds of adapters and no color. Black & white works fine. I replaced the trim pot, and still no go. I went through a "Super Video" mod which includes fixes to luma, chroma, and a s-video mod, and while the picture quality is fine, there is still no color. One thing I did notice, since adding the s-video mod, is that if I rotate the trim pot quickly, I'll get a flash of color on the screen occasionally, but it rarely stays for long. If I swap the pins on the s-video adapter, putting luma into chroma and vice versa, I see the "color" screen in black and white but the vertical sync is terrible. Actually, when I remove the 75 ohm resistor for the s-video chrominance, it becomes more stable, but still has an offset. SEE VIDEO OF SYMPTOMS HERE... Any help would be appreciated. I really want to see color on this Atari!

I explain the whole thing here... :-)

There is a bug in the game which causes it to not have sound in certain cases on NTSC machines. My guess is that if you pop it up on a first revision C64 with 5 pin video that it will work properly.