I wanted to show you 3 PC Diagnostic tools that I use on a weekly basis to give you a quick ever view of how they work. You can buy all 3 together for less than $40 using my links below.

Note: with the component shortage, these go out of stock. If you need an alternative, please ask in the comments.

ISA/PCI Tester
https://www.banggood.com/custlink/K3G...
https://www.banggood.com/custlink/3mK...

Mini PCI/PCI-E Tester
https://www.banggood.com/custlink/Gm3...

ATX Power Supply Tester
https://www.banggood.com/custlink/vD3...