led tv psu repair need help

[Shopy]

hello

i need help on repair a led tv psu

this is a 65 Hisense smart led tv that does not start .the stand by led is on .

i checked the voltages on the psu and i found: 12v is stable .18 v is not stable.it flickers from 18 to 15 v so is the 24 v for the backlight.

i checked all the electrolytic cap on the board with an esr meter and they are ok

i checked the MOSFETs and they are ok.i can't figure what is the problem.attached is a picture of the board

thanks