Since I damaged the pins on the ribbon cable from my screen, I decided to take the good T-Con board and put it back in my dads TV, along with all the other boards from my TV, hoping that would solve what we thought was either a dead main board or power supply board. I figured it would be easier than taking the chassis off of both TVs to get at the other ends of the ribbon cables to replace just those. No luck. The power light comes on, and the screen briefly, and dimly lights up dark blue, then it shuts off again.
If the panel is dead, then I have to try switching all the boards back to my TV, and taking the chassis off so I can swap those cables. But I feel like a dead panel wouldn’t respond at all. I dunno. I hate this shit, but if I spend hundreds of dollars on a new TV without being sure that both these are dead, it’ll drive me crazy.