@danr99897 there is really not much of a test. It used to be that if you can still see your onboard menu then it was your T-con board. If you can't then it was your mainboard. That however has somewhat gone by the wayside. Now, the way I do it, is by measuring some of the more common voltages that you have to have on the T-con board for it to work. If those voltages are all present, it is unlikely that it is the T-con board.
Another thing you can try is to release the cables from the T-con board to the panel. Unplug the power cord, disconnect one ribbon cable from the T-con board to the panel, replace the power cord and turn the TV on. Anything? Repeat the steps but reconnect the previously disconnected ribbon cable. Anything? Let us know what you find out.
Not sure where in the World this TV is located but we really would need to see the boards and in particular the T-con board to see if it has test points for those voltages. Remember, OEM's don't want us to fix those devices, they want us to buy new stuff. that is why a lot of times the schematics etc. are not made public nor are the boards labelled.
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