I apologize upfront for the lengthy post, but I am truly stumped.
About three weeks ago my 23 month old Samsung LN55C650 stopped turning on. Absolutely nothing would happen when pushing the power button. After some research I opened the back to check for bad capacitors. I didn't find any, nor did I notice any other visible issue. Regardless, I decided to try to replace the power supply as this seemed like the logical solution. Needless to say, the problem was not fixed by replacing the power supply. After looking at the connections and setup of the parts, I then ordered and replaced the main board. Once this was replaced things seemed promising. The TV started up and played the start up chime, but no picture appeared on the screen, the backlight was not even on. What would happen is the backlight would flash at start up, but not stay on. I then turned the lights off and shined a flashlight on the screen. I can confirm that the picture is being displayed, but cannot be seen because of the backlight issue. From what I can tell the picture is okay, so I do not think it is a T-Con board issue. Also, the sound does work.
In the split second that the backlight flashes during start up, it looks like the whole screen is illuminated, so I do not think any of the bulbs are out. Considering this, I determined that the backlight inverter must be the issue. As you can probably guess, replacing the master upper and lower inverters did not fix the problem. At this point I am not sure what the problem is, or what can be done. I have looked at the service menu and reset to factory settings. I have also updated the firmware as a last resort. Nothing has worked.
Could it be that the actual backlights have failed? If so, the TV is a loss. Or could it still be another problem? If anyone can help out or offer insight, the help would be greatly appreciated.