Why won't my Xbox360 detect my hdmi?

Okay, I apologize if there are more threads out there like this one but bear with me here. I connected my xbox to my monitor screen using a DVI to HDMI converter cable(the monitor accepted the DVI plug) and it displayed a picture perfectly just without sound. Now, being someone who is a little ambitious and likes to push the envelope a little, I decided that I wanted sound hooked my Xbox up to the tv using the regular AV connectors. No picture, even flipped the switch from hdtv to tv and still nothing. So I thought those cables were no good and I hooked my Xbox back up to the monitor, now I'm not getting any picture.

I even hooked it up to my TV using an actual HDMI cable and still nothing. But here's the thing, I tried the AV cables again with the switch on the HDTV setting and the green lights flashed.

What gives?