Thank you to everyone that helped with suggestions. I tried them on both motherboards, with 2 power supplies. The only component that I couldn't swap out with an alternative was the cpu. So, final judgment is that either I picked up a second motherboard on kijiji and got swindled, and they are both dead, or the cpu got fried somehow.
Here's my economical solution.
The components that are reusable and transferable are the case, hard drive, gpu, as well as fans and other accessories.
So, if I buy a motherboard in atx formfactor, the cheapest amd cpu to drop, and some basic ram, I think that I should be good to go. Am I missing anything?
https://www.newegg.ca/msi-b550-gamin...82E16813144574 at $150
https://www.newegg.ca/amd-ryzen-5-55...82E16819113737 at $120
https://www.newegg.ca/corsair-16gb-2...82E16820233859 $59
About 350 all in from Newegg. Is there anything that I'm forgetting?