My sister got a 46″ Samsung 120Hz TV LN46A630M1F-S that started to turn on/off when plugged in, shows distorted pictures when on, off then on with bright screen with screeching sound reminding me of the TV in the original movie “Poltergeist”. If these are your Samsung symptoms then there is an easy fix for it. Don’t throw the TV away yet. This is not problem of the blown capacitors like my other Samsung.
***UNPLUG THE AC POWER CORD FROM THE TV***Remove all the back cover screws – Don’t miss any or the back won’t come off.
– Check the power board for bulging capacitors. The chance are they’re all good (the top surfaces are flat).