Well there's your problem. I doubt that your USB breakout cable is wired correctly for the camera. Just pick up another one. http://www.bhphotovideo.com/c/product/652385-REG/Canon_4076B001_AVC_DC400ST_Stereo_AV_Cable.html
Once you've got that, it all should connect up properly. Also, I think the Zephyr monitor may only have one AV input. You'd be able to tell if there was an "Input Select" button, and it gave you an Input 1 and Input 2. Input 1 is usually the one you're looking for. I never got much of a chance to play with the Zephyr's monitor though.
Thanks Tom,
I have another question as well. I am shooting a spec commercial on 35mm Film, not sure yet what camera.. but it HAS to do high speed. Is my stock rig capable of running 24v cameras or just 12v? I just bought a set of IKAN LB-130S batteries from B&H. Should I return them, and get something else? And wheres the best place to get Zephyr sled power to camera power cables for specific cameras?
Thanks for helping, I'm a 2 week owner of the Zephyr and thus noob-ish.