jail break works but wont load up on tv

hey wondering if someone can help me out,

i've done the jailbreak process exactly how it says to on f/c, and it all works and goes through fine on the mac, but when i disconnect the usb,(after it says too) and reconnect it to the tv, it loads the apple sign up the goes to a black screen and does nothing, and the light on the box just keeps flashing???

any ideas?