So. This new computer in my office that I've been happily playing with for the last month or so? It looks like the motherboard, or possibly the processor, has become kaput. Luckily it should be under warranty, but it's still going to be a pain and take time, and I hadn't realized how much I'd gotten used to using it instead of my old one.
(On the good side, though, maybe the replacement motherboard won't have a northbridge fan with a noisy bearing. We can but hope.)
Anyone have any ideas on how to tell whether it's a motherboard or CPU problem? It's not even doing beep codes.