if you have same problem( all voltages of psu ok but when you connect the mainboard, voltages drop to zero, except A5V) just cut the PS_ON cable (3.3v) which is come from pin 14...

[QUOTE=username_is_angelo;n3712755]

After several attempts, I left that signal disconnected (though that's not my thing). The TV has still been working for a year and a half, every day for several hours...[/QUOTE ]

Looks like there is a problem with PWR-ON 3.3v rail on both PSU and MB. I couldn't figure out which components were faulty. Then i saw your solution that isolating Pwr-On signal from Psu. It Still works correctly for me too. Thank you so much i will do same and leave it disconnecting. Thanks again.🙏

Exact same problem for me. Did you find any solution ?...

Names Ferhat
Age 38 -
Single,
From Turkiye
:
I am a Computer software technician, Also İ like repairing all kind of electronics.