Within the first couple of months, I noticed an occasional spark and crack coming from the back of the set. From what I'd seen, this wasn't unusual as the various components got settled, but it still seemed odd. About six months into owning it, I came downstairs to find the unit playing sound but showing no picture. I turned off the unit and unplugged it, and when I tried it in the morning, things were back to normal. A few weeks later, this happened again, and again it came back to life. Another couple of weeks later, it died for good. I wanted to see what kind of damage had occurred, so I took off the back of the set, and then I noticed the puddle on the circuit board. Rear projection sets use three very hot CRTs, one for each color, and this set used a liquid coolant to keep these CRTs from overheating. Well, there was a leak which was letting coolant slowly drip out of the system and onto the main board. This was the source of the cracks, and eventually it caused the death of the components.
This happened about a year into owning the set, and I complained to Samsung. Eventually, they agreed to replace the parts, but the labor was up to me, and it ended up being about $600. Well, they replaced the main board, but they didn't do anything about the leaking coolant, so I had another shutdown a few months later. Suspecting the same problem, I did my own makeshift fix, setting up a paper towel inside the set to absorb the occasional drips before they hit any of the electronics.
Well, the set has worked in this configuration for the last three and a half years. I have had other weirdness, though. For about three months, the TV wouldn't accept remote control input, and then it started working again. However, the picture has remained good.
Tonight, I was packing for my trip and cleaning out the Tivo, I saw the screen go dark. I thought it might be a problem with the source material, so tried fast forwarding in my show, and the picture came back. Then it went out again, then it came back. This on/off pattern continued for about a minute, but then I saw it turn into a pattern of color and black lines before going dark.
I think the set might come back up after some rest; it had been on for several hours as I'd been going in and out of the room, a good scenario for thermal failure. I've not yet looked at the back to see if there's obvious board damage. However, I suspect that it's on its last legs. I won't be getting Samsung to pay for any parts with its age, and the labor costs have surely gone up, which means that a repair like my last one would be more expensive than replacing the whole unit. I must have tempted fate earlier today when I was at Costco and passed by their assortment of really cool HDTV sets and thought to myself that one of those would be nice, but I won't consider getting anything until my current set dies. I just didn't want it to happen right now.