Yeah, you're probably right that I should stress test it first. Good point too on perhaps the mobo being a potential factor. The only old motherboards I've had die one me are ones I've killed e.g. playing with vmods or some such after deeming them old enough to be worth the risk. Just underclock, not undervolting as well?
I've worked with a quite number of dead CMOS battery computers, and all they've required is a bit of BIOS configuration upon bootup. But I could certainly give a new battery a go as I happen to have one hand.
I've bought a multiplicity of Seasonic PSUs, and while I'm still generally a fan, there are some GPU compatibility issues with the Focus line to my knowledge. iirc I picked that up at johnnyguru. So that and considering the bit of a premium they are asking for them, I'm considering other options. Why I did not dismiss a be quiet Pure Power recommendation when lurking earlier: johnnyguru
True that ideally I could just lurk for a sale, but I'm unsure when the next good buy will occur. iirc the EVGA ~500W G2 was as cheap as $40 on one sale. Re MIRs, I tend to ignore them. If they work out, then I consider it a bonus rather than something to count on.