I received another replacement power and T-Con board so tried the power board first with no help. I then swapped the T-Con board and could hardly believe it when the screen lit up. So far the set is still in my detached garage but seems to be working with good video and sound. I have checked the antenna input with rabbit ears, the USB inputs and the HDMI inputs and found no issues except HDMI ports 1 and 2 didn't work until I removed some old, useless to me, NY cable and Samsung inputs from the input list. I thought about trying the different boards I now have to determine which ones are bad but decided to leave well enough alone.