hmm given that it is still waiting for the pi-kvm stuff, I could also use the new server hardware as a desktop for now... but what if it's the gpu that introduces faults...

from reading online it seems incredibly unlikely that a gpu would kill a whole motherboard, so the main suspect is the PSU (that was also in there when my last motherboard died)

tried with the PSU from my server, identical boot failure... so motherboard and/or cpu are toast

ohh with 1 ram stick it does go to bios!

wtf, all ram back, gpu back, original psu... goes to bios just fine

memtesting was very fucky, and new motherboards for this cpu seem difficult to source too...

i have a decent upgrade list thanks to @erikk@chaos.social so might just go for that in the end