50LF6000-UB - Screen flickers off and on constantly
Trying to help wife’s friend with her 2-1/2 year-old, 50” LG television… TV powers on and seems to work, with sound, etc. The screen constantly flickers off and on, regardless of the input or any changes in the menu. All of the LEDs flash off and on together in complete synchronization, every 1300ms. While they are on, the screen is visible and you can see the menu and other elements very clearly. Audio works all of the time.
Already tried: resetting TV to "initial settings," turning off "Energy Saver" mode, and I have also replaced the main power supply board with a new board, with no change or improvement. Measured standby voltage at 3.2V.
What else should I try? Are there more multimeter tests that would be helpful? Is it worth putting more $$ into this device?