Look at at figure 9 at link.
Notice how lifetime is much less as temperatures rise? Now did any maker tell you to get in there and clean heatsinks and more every year or so?
So sadly, it is wear and tear and there are many studies to show how this could be a few year device. The part is replaceable but given how Ti talked it up that it would last so long, they didn't make it easy to change out.
But try again with the link at the top of this forum. Just try it.
In the CNET link I have a few other links on a source for the chip, and they have videos on how to change it out.
If Samsung will cover the chip, the labor appears to cost as much as the chip so it's a wash on costs if they do that. I'd let them replace it.
I have a Samsung TV HLT5087SX/XAA. On 9/7/12 I experienced a white dot on my TV, now there are numerous dots on the TV. I called Samsung and they said it was not one of the TV's that had had issues in the past and they would not pay to have it corrected. I have had the TV for 5 years and should have another 5 years at least prior to any problems, this from experience with Samsung TVs and others. Samsung knows there is an issue with DLP chips but refuse to do anything about them. They also stated it was normal ware. The chip is rated at 20,000 hours by TI that would mean I watch TV for 10 hours a day, everyday for 5 years, unlikely. According to this forum I am not the only on with the dot problem on this model. Samsung needs to step up and make it right, if not then another TV maker will get my business.