A) It's an older Macbook Pro running OSX 10.4.11. The screen is not backlit, but if I shine an LED flaslight obliquely at the display, I can just make it out, so it's still booting and everything's there.
B) TV is an LG plasma made in 2010. I've output video to my tv through vga using other laptops before.
C) The dvi cable & dvi-to-vga adapter are both spank'n new.
DVI & said adapter are plugged into to the Macbook and the tv respectively.
I go into OSX's Display Preferences and Arrange the displays, and click turn Mirroring On. OSX recognizes the tv as an LG, and everything. OSX thinks everything's A-OK.
My tv, however, asserts that there is NO SIGNAL coming in its RGB-PC input. TV conveniently "grey's out" the ports which have nothing connected to it in its Input menu, and this one is is not; it is able to be selected which tells me the tv knows on some level that something's there.
This isn't some deep-seeded PC/Apple/LG compatibility issue, is it?
Cables seem securely connected.
Initial web searches are unproductive.
What do you all think, Icrontic?
[Edited for increased clarity.]