@rusty4941 before replacing any boards, let us take a look at the ones you have in your TV. Hardest part will be to take it off the wall :-). then remove the back cover. Now, take a look at the boards and the interconnect cables. Take a couple of pictures of all of your boards cables etc. and post those with your Question. That way we can see what you see. Then check the individual ribbon cables for any tears, corrosion or anything unusual. Reconnect them and make sure they are properly seated.
Now, since we can't see your boards, I make the assumption that there are two ribbon cables that go to the LCD panel. Those should connect to the driver boards. Your TV may have a T-con board or it may have the T-con board integrated on the main board.
Disconnect the power from your TV. Disconnect one of those ribbon cables at the LCD driver boards. Then reconnect the power and turn the TV on. The side that you disconnected should be black but tell us what the other side showed. Now do the opposite side. Disconnect the power from your TV, reconnect the first ribbon cable disconnect the second ribbon cable. Plug your power cord back in and turn your TV on. Let us know what the outcome of those two tests was.
What I do not like are the three wider areas of failure (both ends and the one in the left half of the screen) but we shall see :-) This "switched back to the original hdmi channel (with picture) and it was back to normal." would be unusual for a T-con board failure but we can hopefully identify the voltage regulators on your board and try to determine if those have failed. You'll need a couple of hand tools and a volt/multimeter
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=== Update (03/16/24) ===
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@rusty4941 thank you for those pictures. can you do one more? Take a well focused close up of the EDL-4LV0.3 board. That is your T-con board. I want to see if I can identify the most common circuits that we could have you check. Looks like there was a thermal pad on the IC. Did this just come off while you worked on it? One of the things I always consider is a can of freeze spray. Turn the TV on and then "blast" the IC's with some freeze spray. See if that changes the image. Do the same on the main board. That is teh largest board, teh one with the video input connectors. The board just below the T-con board appears to be the LED driver board. If so, you wont need to blast that. Your backlights are definitely working. Heat is the enemy of circuit boards :-)
@rusty4941 before replacing any boards, let us take a look at the ones you have in your TV. Hardest part will be to take it off the wall :-). then remove the back cover. Now, take a look at the boards and the interconnect cables. Take a couple of pictures of all of your boards cables etc. and post those with your Question. That way we can see what you see. Then check the individual ribbon cables for any tears, corrosion or anything unusual. Reconnect them and make sure they are properly seated.
Now, since we can't see your boards, I make the assumption that there are two ribbon cables that go to the LCD panel. Those should connect to the driver boards. Your TV may have a T-con board or it may have the T-con board integrated on the main board.
Disconnect the power from your TV. Disconnect one of those ribbon cables at the LCD driver boards. Then reconnect the power and turn the TV on. The side that you disconnected should be black but tell us what the other side showed. Now do the opposite side. Disconnect the power from your TV, reconnect the first ribbon cable disconnect the second ribbon cable. Plug your power cord back in and turn your TV on. Let us know what the outcome of those two tests was.
What I do not like are the three wider areas of failure (both ends and the one in the left half of the screen) but we shall see :-) This "switched back to the original hdmi channel (with picture) and it was back to normal." would be unusual for a T-con board failure but we can hopefully identify the voltage regulators on your board and try to determine if those have failed. You'll need a couple of hand tools and a volt/multimeter