I have had this Mac mini for just over 3 years and it has never crashed or frozen until an hour ago. There might have been a few Safari restarts required in the first year and that is the only reliability issue that I can remember. The Mini was running Safari and Mail and I had not touched it for a few minutes and the Screen Saver had not yet kicked in. I run dual displays and I noticed one of the displays had a slightly "off" colour on its desktop which is normally "solid aqua graphite" on both displays. The Mini was frozen and unresponsive. A reboot seems to have brought it back to normal. I wonder what might have caused the crash. Any ideas? I have not changed the Mini peripheral cables, RAM, etc for a long time. About 10 years ago I had an old Windows computer that would sometimes freeze when the house gas furnace fan motor turned on (no problems since then). Maybe I have a "dirty AC power" issue in my house.