iMac 27" to TV HELP!!

[nickr1]

I have an iMac 27" with the mini DisplayPort HDMI cable connected to my LG Plasma and it doesn't work.

Now i have tried with my brothers smaller intel iMac and it works fine. It actually picks up the signal right away when it's plugged into the tv and works. Did Apple change something on the 27"..? Am i doing something wrong?

Can someone help plz.....

 

[Knoodles]

It should have recognized it. Try opening System Preferences>Displays and click on the Detect Displays radio button.