Harmony Cart issues on a 7800

[bszarek001]

Hi Everyone,

 

I recently obtained a 7800 via a lot I purchased. Initially, while the game video and audio were working fine, there was a ton of static on top of the game audio. I went into the RF board with a hex wrench and adjusted the video/audio output and finally got it to where everything appears perfect. I wanted to run the 2600 diagnostic cart from the Harmony Cart, but for some reason, this is the only cartridge that will not function on my 7800.. I've tried 2600 and 7800 games, probably about 8 of them, all work perfectly.

 

I will also say I have a modded 7800 that i use as my primary 7800 and my HC works perfectly in that.

 

Is there a known issue with the HC working on a non-modded 7800? I can't imagine a reason. Any help would be greatly appreciated. Thanks!