Back from South Korea and more or less whole again, although about 4 hours out of phase with the rest of the world. A complete report of what I did on my travels will be forthcoming soon, unless I forget or never get around to it.
Meantime, mugwump2 completed his repairs and arrived home before I did after his trip to "triage" (that's really what they called it). Yay!
Unfortunately, while typing away at some stuff this afternoon, mugwump2 suddenly died again, just as before. Boo!
Thinking more about the problem, it seems it could just as well be an overheating problem (mugwump2 was running a fever at the time of failure, and had just been charged with some particularly complicated computations). So maybe it's a cooling issue. I'll see how often it reoccurs, and whether it gets annoying, before thinking about whether it's time to start planning the purchase of mugwump3 already...