What could be wrong if my LCD tv powers off and on constantly. Samsung UN55KU6290FXZA

Hi Doug, you already diagnosed your set when you said it flickered like a dying light bulb, your LED backlights have failed and need replacing, you should be able to get parts from shopjimmy, stay away from ebay for parts

Chances are your LED backlights are bad, common failure on this model TV, you can unhook the cable going from the main to power supply and if the lights are working they will come on, if they don't and I don't think they will the strips have at least one open diode

the voltage is ok doo you have constantly 150 v if not led blocks is bad

Hello,

Power supply board have problems,just not dead yet.Replaced the power supply board,will solved this problems.Tries websites like Shopjimmy.com,Ebay.com to buy a refurbish power supply board for the replacement.
Hope this help in solving the problem

u have bad capacitor on power supply

It sounds like the power supply board has some bad capacitors that need to be replaced. Samsung is covering the cost to repair this problem on some models. You can call 1-800-samsung to find out if your unit is covered.

http://www.lieffcabraser.com/defects/samsung-lcd.htm

yes you are right it is the power supply, look for bad capacitors.

It sounds like you may have some bad capacitors in the power supply. These can be replace by a competent tech without replacing the whole board.

yours DLP TV not a LCD.
LCD has on one light with red.

If the DLP likes that.
1st -- check the thermostat
2nd -- check the power board.