Posted April 06, 2021
I don't know how I can approach the warranty route as I can't even properly describe the problem. Seeing as it is rare and random, there's no way of reproducing it.
Will have to check if everything is plugged in properly, as Trooper1270 suggested.
The other thing you could do is to try to reduce the power load on the system during boot, which might highlight whether it's a power supply issue (e.g. remove your add-in graphics card). The problem with this is that while it might help diagnostically, given how rare the issue you describe is, you might have to go quite a while with onboard graphics to see whether it helps.
Otherwise, try to video record it happening when you boot up (on your phone or something) - you might want to start to build up some evidence.
Otherwise, live with it for a bit and see how it develops. There is a risk that if it's a power supply failure that it could fry the PC, so back up any data externally. However, I'd expect (if this is power supply) that it's still early stage. I've only had one power supply fail on me before, so I'm not the best in this regard, but I probably got lucky (smell of burning, computer shut down, no component failure)
