Tv won't turn on and taking so long to turn on

My Tv took to long to turn on, i changed all electrolytic caps and still the same problem.

I bought a used power supply for it, and it worked for couple of hours before the same problem back.

I tested the LED light and they r working.

Also tested all caps and they r pretty good.

The Final thing i noticed that the power supply making low noise like wave noise, like when you turn on ur tv and the power supply initiated. This noise goes stable, but in both of them the noise is unstable.

Any Help!