Intermittent power LG LED tv

Good morning gurus. I have an LG tv that until recently has been upstairs and used very little since new. Recently we moved it downstairs. Suddenly, the stand-by light would not be on and the tv wouldn't work. Then a few hours later the light might be on again and the tv would work but all the presets will have gone back to default. I watched a couple of non-specific vids about trouble-shooting. Of course, when I removed the back, it was working normally so, I suppose, testing would be futile. There are what I suppose are test points of 11, 5 and a dot (ground?) and a legend that gives me some voltages. Getting about 12.9 at a point where the legend says 13.2.

Any advice? Thanks for reading.

Edit: I have it laying face down on the bed in the spare room. I walk in and the stand-by light is off. Then it flickers and is on again. I found a power supply online for $30. Might take a shot versus buying a new set.

My grandson had the same problem with one. It seems that LG used some bad caps for a few years on the main power supply boards. I found a guy on Ebay that repairs the boards and resells them. They sell kits to do it yourself but there are a lot of surface mount parts near the caps and didn't trust my self to repair it. Bought the board and the TV has worked for over a year now with no problems.