Indeed. The fact that it seems to be arbitrary drives does point to something deep in the motherboard rather than anything else. A dodgy cable, socket or component would only affect the recognition of the one component. It's irritating.
Yup. Those are usually the things I get stuck trying to sort out at work. The things you see once every 3 years or have never seen before. Some days I hate computers!
The power supply's almost new and 800w, though I guess if it's new(ish) & the issue is new(ish) too, there could be a connection. But 800wtbh?
Try and different power rail maybe if you can? This is probably where my advice ends!
You could have him test the rail by licking it right? Am dead?
Have to tried reseating your RAM. If that doesn't work, try reseating Little Blue's RAM. HTH TBH.
I had a much older-than-that mb drop one whole ide channel due to leaky caps. The other kept chugging along though.
The motherboard in my last computer popped some caps around the PCI-E slot and was corrupting the graphics/BSODing.
I bought new parts (complete upgrade) and then realised I could put the graphics card in the second GPU slot. Still, good reason for an upgrade.
You'd think the slightest short would toast the whole thing.