Weird interference in my 2600 Jr

[slbailey]

Just did a cap kit replacement and composite mod to my 2600 Jr (granted it's my first one so it's highly possible I botched something) but now I'm getting this weird interference / artifacting in the video signal.

 

Any of you guys know what I might look into to troubleshoot this?

[AtariSphinx]

I would start by double checking to make sure the capacitor values at each location are correct especially the one near the voltage regulator.  I found in mine someone had done a recap and put in the wrong value causing interface.  Changing it fixed the issue.

 

Was the system fine before the changes?

[slbailey]

I have no idea.  It wasn't working before I recapped.  AFAIK, the kit I used had 4  4.7uF caps and 1 2200uF and it's kind of hard to mix those up

 

Can I check them to make sure they're working correctly?  Good solid solder joints?  My soldering skills are not perfect by any means.

[+Stephen Moss]

11 hours ago, slbailey said:

AFAIK, the kit I used had 4  4.7uF caps and 1 2200uF and it's kind of hard to mix those up

Yes, but it is easy to put them in the wrong way round, so you might want to double check that as they do not work as well or generally for very long in back to front.

 

If you are not sure which end is which, then there is usually a white/grey line down one side (usually with a minus sign in it) that points to the negative (GND) terminal, and on axial (one lead on each end) the lead at the metal end is usually the negative end. 

[slbailey]

I will check that out!  Thanks for the tip

[jer10571]

Double and tripple check all your work, just to rule that part out. Make sure all your solder joints look good with no cold solder joints.

 

If you power it up with the case off, try to 'wiggle' the 2200 axial capacitor and see if the signal changes. If it does, check your soldering. If that looks good replace that capacitor again (you can even put the old back in and see if it looks better). Also check the voltages on your voltage regulator.

 

I was watching a video on YouTube where gametech was explaining that sometimes that capacitor can cause an interference issue.