After doing some research, I find a YouTube video stating it's a bad internal power supply board. The video shows how to remove the board. However, the company that built this display for Apex used several different power supply boards through the life of this model, and the are all incompatible with each other[emoji35].
Before any one tells me to contact Apex Digital, don't even bother. Apex digital went belly-up in 2010. I've tried all the major TV parts houses, and none have this part.
I do know that some tv core manufacturers, like Funai, rebrand their sets for Sylvania, Emerson, and Symphonic. A lot of times parts for these brands are interchangeable, just by looking at a cross reference list supplied by Funai. I have not seen any such list for Apex Digital, or who manufactured the set, which is the second largest TV manufacturer in mainland China. Does anyone here know of a cross-reference and replacement to Apex Digital part number1204H0559A/1, and know where I can find said part?
Did the YouTube video specify that it involved bad capacitors on the board? Just wondering how long it would take to troubleshoot a single bad capacitor and replace it. But then with everything being so modular, I'm probably thinking "old school" to the point of impracticality. Like seeking a tv repairman.