How to fix Samsung LED TV that has no picture and no sound

SOURCE: Samsung LTN1765 has blinking green power indicator, but no picture or sound

Try replacing C51, a 10 microfarad 16v. surface mount electrolytic. It's near IC23 on the upper center of the board.
This part had high ESR on a couple of sets I serviced which
kept the power supply from starting.

SOURCE: Samsung TV won't turn on- trying to fix it. A challenging problem

I had the same problem. I live in NJ and called the local authorized "service provide" listed on the Samsung website. What a joke. Quoted $350 just to show up, never showed up. So I opened my own TV. Took off the plastic back (10 screws) took off the large metal RF shield (12-14 screws) and noticed a blown component. The markings on the component were KL15L and it is apparently an NTC Thermistor. Obviously it got fried and not knowing if there was other damage I decided to set out to replace the entire Power PCB Board Assembly and not the component. There were two part numbers on the assembled board (BN97-00457E & BN94-00622E). After searching online I also found a suitable replacement number for these (BN96-04896A). I found two places who claimed to have the part or have it on order (shopjimmy.com and vancebaldwin.com). After placing orders with both and having neither come through, I broadened my search and found out that the LNR409D was basically the same model as my LNR408D so I looked for its Power PCB Board Assembly part number which turned out to be BN41-00521B. Google search for that part number showed the item available on ebay. I bought it a week ago (ebay 260311519904) for $144 plus $12 shipping. I removed the bad board an hour ago (6 screws about 7 connectors) installed the new one, plugged in the connectors, replaced the covers, plugged in the TV... AND IT WORKS!
Suggestion: If your TV is out of warranty then open it up (what have you got to lose) and see if the problem is obvious and maybe something you can fix (replace) yourself. The parts, spare boards, etc. are out there if you look.

SOURCE: Samsung LNR408DX/XAA Powers on with sound but no picture

I think you need to exchange the Main Board.

SOURCE: Samsung ln t4665f : Power Light On , No Picture : Clicking Sound

there is a soloenoid type switch that fires the TV up this has failoed. its like a neon or fluoresecent tube that has a faulty starter switch light tries and tries but never quite makes it when it does get going it has that purple smear in the tube. that is the simple explanation for your problem. part is about $60 labor is unkinown as i am not in USA but looking at some of the rip off charges I am glad i dont have the bill

SOURCE: samsung lcd tv ltm1755b won't turn on (power light stays red)

I had a 26" Samsung LCD that wouldn't turn on, and the red light stayed on too, so I knew it was getting power. I found some info out there and figured out how to fix it. Also made a video to show others. I'm a complete newb so if I can do it, I know a lot of others can too. Make sure you research stuff and be safe when fixing it. I take no responsibility if you mess up your own TV! But like I said, I fixed it, so I figured almost anyone can. Also, it only cost me $1.40.

http://www.youtube.com/watch?v=vWKlex7kA7A