I began having problems with my Samsung HLS-5679W LED DLP Rear Projection HDTV again early in January 2010. On January 22nd, I got a Fan #3 error followed shortly there after with nothing: the set would not power on at all. Before it totally went out, I purchased some reconditioned fans to test. The #3 fan is located near the inputs, over the cable card slot (which I have never used). Replacing the fan did not fix the issue.
Based on a previous power-on clicking issue I had experienced with the HDTV that required replacing two capacitors on the main power supply board, I pulled and inspected the power supply. Sure enough, there were now four more blown capacitors. The two I had replaced back in February of 2008 were still fine. Also the four, now bad, capacitors were all ok two years previously. I guess it just took them two years longer to go bad. My theory has been that Samsung received a very large batch of bad capacitors from one of its suppliers. Other capacitors on the board from the same company are all ok to this day.
Of course I didn't have the correct replacement capacitors just lying around so I had to order them from Parts Express which is were I ordered the original replacements back in 2008. Once I received them on January 29th, I followed the general capacitor replacement procedure outlined in the AVS Forum thread covering the Samsung HLS-5679W. Now I can't do the best soldering/desoldering in the world but I made it through ok. After about 20 minutes, I had the caps replaced and the board back into the HDTV. The whole process was faster and much easier the second time with my past experience. I fired it up and it worked again!

It's great having the HDTV working again of course but I also hope to give it to my brother onced I get a new 3D HDTV and I really wish it doesn't give him any trouble. I need to have something to watch until I get the new HDTV of course too.
I've posted (#2592) the following pictures within the AVS Forum thread: Six New Capacitors, Bad Capacitors - Top, Bad Capacitors - Bottom, Samsung HLS-5679W Power Supply (a schematic I created detailing which caps I replaced and what I replaced them with).