Samsung UE39F5000 power supply no start no backlight
November 4, 2021
* red LED flashes
* if I disconnect the Main Board (MB) from the source board, the backlight does not light up !!!
* all LEDs / number 91 / are OK
* I checked all the capacitors
* I checked all the diodes
* I checked all the FETs
* measured voltage when the Main Board is disconnected
* if the Main Board is connected the voltage pulsates
ECO_ON / OFF —
BLU_ ON / OFF 2.9V
but I managed to turn on the TV normally by accident and both the backlight and the image went – the error is definitely in the power supply
if i want to turn on the power board on a table without a main board how can i do it? should the PS-ON pin be grounded ???