the issue happened today, and i tried disconnecting somethings to make it work. on the right side of my case where all the cables are its quite conjested, i disconnected and reconnected the ssd and one of the lighting for the case and then it magically worked again. probably a coincidence but ill find out in a few days if it really has fixedYou need memory to boot. You don't need any storage drives.
I haven't read the full thread, but have you tried taking it all out of the case and setting it up on the bench? The motherboard box usually makes a good platform.
I've always tested everything together before I install anything into the case. It can save a lot of time and effort.