Original post by: George A. ,
I'm not exactly sure what the issue is (if your sound is getting through, the TV must not support that resolution) but [https://www.amazon.com/Tendak-Composite-Converter-Adapter-Supporting/dp/B00KBQZC4M/ref=sr_1_1?ie=UTF8&qid=1492007486&sr=8-1&keywords=hdmi2av&refinements=p_72%3A2661618011|this] should fix it. Or, if your TV has a VGA input an A/V to vga also works. I have the same problem, except that my gamecube doesn't work with my A/V receiver. It works when I plug it into my TV, though. If your TV has the setting for it, change your resolution to 680P or 480P. Hope this helped!