Can't get picture from my mid '09 13" MBPro to a Vizio TV using a display port to HDMI adaptor I have a Monoprice display port to HDMI adaptor and am connecting my Mac Book Pro to a 42" Vizio LCD display. The Displays system prefs show the Vizio display, but it shows "No Signal". If I toggle the input select on the Vizio, the MBPro, and the Vizio, will flash to black intermittently, but never stabilize and show a signal. I've changed HDMI cables. Could it be an issue with the Monoprice adaptor? I also downloaded SwitchRex X, installed it on the Mac, and it shows the Vizio resolution to be 1080p, but still no signal/picture on the Vizio.
I have MBPro and MacMini with some noname (fitTek) DP to HDMI adapter and it works fine. 

Try to configure resolution to be optimal for External display or to extend it (use as two monitors). 

To be honest I always tried over my Onkyo Receiver- never tried directly into TV