Computer to tele help

Help! I recently moved and i had my computer running audio and video to my television in my bedroom and after i moved it didnt work anymore. Im running a geforce 550ti video card with a hdmi micro output and i have an adapter plugged into a 50' hdmi cable running to my tele. the problem is when i plug in my cable to the television the computer goes blank, so i know its getting som kind of video, but my television is blank as well. So i am unable to play with the settings and set up my duplicate screen setting. I only see my1 video output when i open the screen resolution and that is my monitor.