Ok I went over everything with my MM and it checks out except for one thing. Checking the green line gives results that fluctuate. On diode mode it checks out clean, but if I set to x200ohm it's all over the place. From 0.01 to 0.67 and sometimes flies right to INF.
I plugged the cable back in again, and this time I got a picture, but everything is tinted green. Sync is on green with component right? Might there be a capacitor hiding in that line? I know no other explanation for such a variation when testing resistance, but then again I'm no expert!
Mind you, if that lines the problem why is red and blue missing? Green I know, on component, is "everything else".
Edit: I fixed it, after cracking the housing on the connector, I can see why the ground pins test ok on the shielding, as they're wired right to it. From there, the video ground was making intermittent contact with the pin it's jumper across from the other grounds.
Looks like the wire was blown right apart out of the insulation, as the insulation was still in one piece, just with a hole in it and a split wire hanging out.
Soldered it back together. 100% fixed! Now to figure out why the hell my TV did this......