I am making a custom motherboard that hold one of the AM4 cpus and a one of Amd’s laptop graphics cards. I also have to add a chipset that is compatible. The problem is I can learn how to make a circuit board but i have no idea of how to wire everything together so something like a blue print would really help.
Good luck in getting any type of blue prints from Computer manufacturers. Generally those types are not available to the public.
You might need to have to sign a NDA (Non-Disclosure Agreement) contract with the Manufacturer to get access to any type of propriety intellectual properties like that.
Building a Motherboard you will need to have at least a Bachelor's degree in Electronics. They are very complicated piece of electronic hardware. Unless you have a team working with you to design and build a motherboard that has knowledge of all aspects of motherboard hardware.