Chosen Solution
On the first day that it started acting up, it randomly turned off and immediately back on again, but this was the first time and I thought nothing of it. The next day it starting happening more frequently and the following day even more until on that same day it turned off and was completely dead. There was no red standby light. A while later it automatically turned on again and acted up like before but this time it completely died when it turned off. Now it’s gotten to the point where it’s off with a red standby mode light, the TV won’t respond to any buttons. If I try to turn on the TV using the power button from the Sky remote AND the TV remote, it won’t respond - the red light won’t even blink. It won’t even respond when pressing the touchscreen power button on the TV either. From this point it just randomly turns on, stays on for 10 minutes or so then either turns off and on or turns completely off, with no red light. I’ve opened the back and checked the insides; I’m no mechanic, but everything seemed fine to be. The capacitors seemed normal, no fuses were blown, it looked like everything was in perfect condition. However, there was quite a bit of dust around some of the electrical parts and everywhere in general - could this be a cause? I’ll try cleaning it anyway just to check. Please help.
Zak-A-42 disconnect every input and very other piece of equipment you have connected to your TV (sound bar etc.) then unplug the set. Leave it unplugged for 10-15 min then hold the power button down for about 30 sec. and after that plug your set back in while keeping the power button pushed. Once your set comes on let go of the power button. See if that changed anything. Only connect one input source. Since you already removed the back post some images of all of your boards with your question. that will allow us to see what you see. Use this guide Adding images to an existing question for that. You will need at least a multimeter to check your TV further should it become necessary. Update (03/14/2018) Zak-A-42 you did not mention the 3 blinks before. Even so Samsung does not offer any error codes 3 blinks is usually caused by an issue with the power communication to the boards. The TV is in standby mode and trying unsuccessfully to come out of it. This would definitely point toward a power board issue. The power board is one in the first picture. Post another image just clearer and maybe zoom in a bit more. It currently is hard to make out when enlarged.
Reset the tv, after reset make sure you disable all the powersave options.
