2600 Jr Composite Video Mod - Old Style: No video on some TV

ShadowStitch · Post by **ShadowStitch** » Thu Nov 30, 2006 5:18 am

As the topic states, I recently completed the Original Benheck composite video mod for my little Atari 2600 Jr.

Strangely enough, it works perfectly fine on my Computer's ATI TV Wonder input (well mostly anyways, save for some faint vertical banding) but won't produce any sort of picture at all on my older RCA CRT TV. The screen distorts like it's receiving some sort of video signal, but it assures me there's no video input. I tried connecting it through my Sony VCR, with the same results.

Could this be the fault of the older mod versus the newer mod, and the recurring issue of Television compatibility?

If so, does anyone have an extrapolation of the 2600 Video Mod Rev 2 that I can apply to the 2600 Jr? As far as I understand it, the diagrams on this page are only for the 4/6 switch models?

http://benheck.com/book/support/Atari2600VidMod.htm

If not, does anyone have any suggestions regarding what might be the real problem? I've tried adjusting the two pots and nothing has changed for the better.

Any advice or help would be appreciated. Thanks!

ShadowStitch · Post by **ShadowStitch** » Thu Nov 30, 2006 2:27 pm

Okay, so I tried taking it to work with me and tested it on a Panasonic TV. On this one, I got a rolling screen and dark picture.

I'm still experimenting, but I can't help thinking there's something I've missed.

Post by **Sparkfist** » Thu Nov 30, 2006 10:04 pm

It's not quite as up-to-date as the 4-switch componite mod Ben's made, but this should work.

ShadowStitch · Post by **ShadowStitch** » Fri Dec 01, 2006 2:35 am

Thanks Sparkfist!

That's the mod I followed, and I was getting the aforementioned results... but I finally figured out what the problem was after reading throughly over another site's 2600 video mod -- I needed to put a short wire from the Luma point (directly above and to the right of the Chroma point) to the common composite video lead.

After that, it works great on all the TVs! The color is very nice, and except for the faint vertical lines (Which I never seen to be able to avoid) it's exceptional.

Klefmung · Post by **Klefmung** » Fri Dec 01, 2006 2:53 pm

I will tell you how to do Ben's newest mod on a junior. Just follow the traces on the resistors he pulls of on that mod back to the Stella. Then follow the traces off the same pins on the Stella to the same resistors on the junior, then wire the same circuit and follow the same directions. ^_^