Colecovision Video Interference, Help Wanted

[Jeremy Popp]

(thought I'd post here, didn't get any responses in the Hardware section)

I'm looking for some technical help with a colecovision console. I'm getting some sort of minor video scrolling interference since I've owned it the past couple years. I've ruled out the Power Switch (even bypassed it to double check), and it's not the power supply since it works great on another unit I have. Video below:


https://youtu.be/DIMJcQ0Ow80


(really noticable on the words popeye and olive near the top)

Some notes:
I A/V modded the console, and the interference shows up AV out and via rf coaxial
Does not show up via the Atari 2600 Expansion Module (unless it's very minor, doesn't appear that I can tell)
I've reflowed most of the solder joints related to power and grounds
I've visually checked for broken solder joints and find none
It's on every game, not just some.

I have some small electronics experience, but not much. I'm am an amateur, but not afraid to dive in and learn more. Thanks!

[rednakes1]

Bumping this old thread because I have been pulling my hair out trying to fix the same issue. Jeremy mentioned he eventually sold this CV and got another one later that worked better. So it doesn't look like an issue with his location and power socket.

 

I'm attaching a photo to demonstrate what I am seeing. It's a set of random lines on the screen that show up, disappear after several seconds and then show up again in the same or different orientation. It drives me nuts, especially in games with a blue background (eg. The skill select screen, or Evolution title screen).

 

This problem is most visible on my AV (composite) connection but also shows up on the RF coax input as well, though not as noticeable because the lower quality hides it a bit. I've tried the transistor AV mod as well as the op amp version of the mod, and neither rectified the issue.

 

I've also tried two different power supplies, cleaned the power switch and PCB, and tried different TV sets (CRT and LCD). I don't want to waste any more time on this but was just hoping someone can help out.

 

Mine is a Revision J motherboard.