Trouble Connecting Imac to Samsung 6 series tv

I Recently got a Samsung LN46B610A5F (Samsung 46" lcd 1080p HDtv) and I have an Intel G5 Imac (I think its G5, got it in either 2007 or 2008). I Purchased a min-DVI to HDMI adapter and a HDMI cord to connect the two, but my mac doesn't detect it as a display device. Apple is clueless and Samsung support doesn't even know their own tv's. Anyone have any advice? even the instruction booklet says it's Mac compatible, but nothing I do makes it work. Help?

Did you change the TV input (using the remote) to correspond to the one you have the Mac plugged into?

If you did this, try moving it to the HDMI # 1 connection.

(You can't have a G5 Intel. A G5 would have a PPC chip. If you purchased it new in '07, then it would be Intel and is just called an iMac)