Total expenditure: about $500. Turns out it needed a new motherboard, roughly $100 from Computer St. Louis (10011 Watson), who are really really great people with a really great shop, even better than they were when it was a Computer Renaissance franchise. In the process of proving this I also swapped out the CPU and the power supply. I don't regret either purchase; I'd been leaning towards going from the cheapest socket 939 processor I could find (when I bought the machine a year ago) to one of the best, it's already making a big improvement in my quality of life and I was leaning towards buying that this month even before the meltdown. The new power supply, and a better case fan I sprung for for $10 from NewEgg.com, may not have been necessary in hindsight (or they may have been) but either way they also brought the sound of this computer down from "roaring jet engine" to "gentle hum," another big improvement in my quality of life.
The single biggest purchase wasn't directly related to the meltdown, but I still count it: I sprung almost $200 for a good-quality uninterruptible power supply, something with enough battery backed up outlets that I can run the computer, monitor, cable mode, and hub for about an hour during a blackout. But worrying about Ameren-ron and the approaching summer storm season, while relevant, weren't why I chose to do this now. I chose to do this now because I'm pretty sure the fact that I didn't replace my old UPS when it died are why my motherboard (and almost certainly power supply, and quite possibly CPU) died. I was scratching my head over what could possibly have gone wrong that I went through yet another power supply in not much more than a year, and then I remembered something almost certainly relevant.
About a week and a half ago, now, I had a rough morning where three times in less than an hour we had five minute power outages. Each time, I had no sooner concluded that okay, this time I think they must have it fixed and turned the computer back on, scant minutes later the power blew out again. So during the 3rd blackout I walked around the neighborhood, and concluded that it was at least three blocks that were having this problem, then called Ameren-ron's national outage reporting number. After a couple of minutes of poking around in her system, the customer service rep asked me, "Wait, do you live anywhere near St. Ann?" Yes, a couple of miles down the Rock Road if that's close enough, why? "I've got a report on my screen that a trash truck ran into one of our power poles. The report says that at this time, both the truck and the utility pole are still on fire." When the power came back on, I checked Ameren's system outage map, and sure as heck, it showed almost all of St. Ann and half of Bridgeton as blacked out briefly. And for that kind of a problem, for the grid at near peak hours flickering a bit while rerouting around that big of a hole in the delivery network, I don't hold it against them. And in fact, even before the fires were put out they had my neighborhood nearby up and running solidly.
But yeah, no computer likes having its power yanked out from under it that often, that hard, that fast. And in hindsight I can see some symptoms between then and when it finally died that my power supply had taken a lifetime's worth of abuse from that and was about to give up for good. So yeah, I've learned my lesson once again, after having repeated this mistake an embarrassingly large number of times over the past 23 years, that if I'm going to have a computer up and running any large percentage of my days, that computer really does need to be on a UPS. But somehow, after each UPS wears out on me over the years, I go through this all over again for thinking that it's not that urgent that I replace it right away. And each time it ends up costing me a substantial percentage of the cost of a whole new computer. Maybe this time, against all odds, I'll actually learn from it.