Atari 2600 s-video mod issues

[Arsonist00]

Hello, I hope you can help!

 

I have installed an s-video mod board from here to my pal, black label Atari jr.

 

When I boot a game the picture looks clean and bright for about 12 seconds, before turning very dim and losing colour. The game plays fine, and there is no issues with sound, just really dark after 12 seconds.

 

So far I have checked all my soldering for continuity, pins 9 and 13 are lifted, the bottom of the mod board is taped, and there are no visual signs of bad capacitors (my initial thoughts). Any ideas what could be going wrong or what I should check next?

 

[Arsonist00]

So I redid a couple of solder joints but no change. Then I bought a new 9V 1A power supply and it's now working fine!

I think the ancient one I was using was either dying or didn't have the amps to power both the console and the mod board.

Hooray!