Poor audio and partially desaturated video problem

[azure]

This is what happened. My Atari 2600A (rev 9) was working fine until the power cord got tripped over and yanked out while the case top was off. When the cord yanked out, it broke the J201 power jack. The machine still worked fine by plugging in the power and holding it in. There was clear video and clear audio.

 

I got a replacement power jack (a switchcraft), soldered it in, and tested that there was video and audio. The video is clear, but it's partially desaturated: meaning the colors are no where near as vivid as they once were. It's not displaying in black and white. There is color, but it's at about 50% saturation. The colors on my 2600 Jr are very vivid in comparison. It was working fine after the power jack broke and before I soldered in the new one. The audio sounds close, but it's off. There's a small amount of audio distortion.

 

I'm not sure what's going on here. Anyone have any suggestions? I compared the video/audio between the 2600A and the 2600Jr using the same cartridge, same power adapter, and same RF cable.

 

Incorrect soldering? Damage due to static electricity? A short somewhere?

Edited January 15, 2018 by azure

[Jeremy Popp]

This is what happened. My Atari 2600A (rev 9) was working fine until the power cord got tripped over and yanked out while the case top was off. When the cord yanked out, it broke the J201 power jack. The machine still worked fine by plugging in the power and holding it in. There was clear video and clear audio.

 

I got a replacement power jack (a switchcraft), soldered it in, and tested that there was video and audio. The video is clear, but it's partially desaturated: meaning the colors are no where near as vivid as they once were. It's not displaying in black and white. There is color, but it's at about 50% saturation. The colors on my 2600 Jr are very vivid in comparison. It was working fine after the power jack broke and before I soldered in the new one. The audio sounds close, but it's off. There's a small amount of audio distortion.

 

I'm not sure what's going on here. Anyone have any suggestions? I compared the video/audio between the 2600A and the 2600Jr using the same cartridge, same power adapter, and same RF cable.

 

Incorrect soldering? Damage due to static electricity? A short somewhere?

 

I cannot say for sure why a power jack issue would cause color and audio issues, however....

 

On the left side of the motherboard, you will notice a clean wide flat potentiometer with a slot for a screwdriver to adjust. This is color adjustment, and I would recommend using a plastic screwdriver if you have one, or just turn the dial by hand. In some cases, using a metal screwdriver can cause interference.

 

As far as audio, it could be that the 2 820pF, 50V Polystyrene Film Capacitors have failed which are on the right side of the motherboard. One more place to check is the RF modulator, which is the big silver metal box on the right side. It has a hole, where you can stick a small screwdriver (again plastic if possible) to adjust the signal, which can effect color and audio quality.

 

In the end, both issues could be just a bad RF cable. Good luck.

[azure]

I cleaned out the solder and hand placed the power jack into the motherboard today (unsoldered, just loose held in by friction.) I connected the power for a test. The audio seemed fine this time. The video was a little washed out, but it's a lot improved. I think it may have just been a bad solder connection, so it was either a bad grounding or short. I'll try the color adjustment to see if it improves it even more.

 

As for the desaturation, I've gotten a second 2600A console (rev 14). It was a mint condition console with barely used joysticks and never been used paddles, so I had to have it. I compared the video to the first 2600A and they seemed just about the same. I realized I was originally comparing the video between my 2600Jr and 2600A. I guess they just have different video characteristics. The Jr has considerably stronger color saturation and cleaner picture. The colors in Pitfall are a bit too green though, but looks fine.

 

Btw, those new paddles are smooth as silk. Incredible. I am probably going to store them to avoid wearing them out. If I get this old 2600A fixed up, it'll be my daily machine. The mint condition machine is going in storage.

Edited January 18, 2018 by azure

[Jeremy Popp]

I cleaned out the solder and hand placed the power jack into the motherboard today (unsoldered, just loose held in by friction.) I connected the power for a test. The audio seemed fine this time. The video was a little washed out, but it's a lot improved. I think it may have just been a bad solder connection, so it was either a bad grounding or short. I'll try the color adjustment to see if it improves it even more.

 

As for the desaturation, I've gotten a second 2600A console (rev 14). It was a mint condition console with barely used joysticks and never been used paddles, so I had to have it. I compared the video to the first 2600A and they seemed just about the same. I realized I was originally comparing the video between my 2600Jr and 2600A. I guess they just have different video characteristics. The Jr has considerably stronger color saturation and cleaner picture. The colors in Pitfall are a bit too green though, but looks fine.

 

Btw, those new paddles are smooth as silk. Incredible. I am probably going to store them to avoid wearing them out. If I get this old 2600A fixed up, it'll be my daily machine. The mint condition machine is going in storage.

 

Great that you have one to compare. On the subject of color saturation, check out the following topic:

http://atariage.com/forums/topic/241317-improved-color-for-your-4-switch-woody-a-public-service-bulletin/

 

This mod will probably make the colors more like the Jr.

[azure]

Thanks for the link. However, I ended up turning the color adjustment dial inside and the color looks great now. Resoldering the power jack and adjusting the dial made the video look like new.