So, I had (have) a strange issue that my local PC repair shop diagnosed as probably my CPU, so I'm wondering if you've ever heard of this kind of thing before.
Full story: I bought (supposedly all new components) the things to build a new PC (my first build), made sure they were all compatible, all that.
Here's a link to my parts list from PC parts picker: https://pcpartpicker.com/list/bKpwwc
I originally bought a GIGABYTE Z790 AORUS Elite AX motherboard, but when I plugged everything in and tried to power it on for a pre-install boot test, it hung at the CPU light. I tried everything I could to troubleshoot and diagnose the issue. I unplugged everything and plugged them back in. I jiggled the wires. I looked for scorch marks where something might have shorted. I checked the pin array (THREE TIMES!) I reseated the CPU, GPU, RAM, AIO cooler, and M.2 SSD. I took every component that was connected off one at a time including the CPU before powering it back on, all to no effect. It always had the same problem.
I figured that the motherboard was most likely faulty, though wasn't certain, returned that to my vendor (Amazon) and ordered the Aero D as a replacement (because it was around the same price point but had a hex display which I thought would help the next time if I needed to troubleshoot). The Aero D came, this time I went to a PC repair shop and built my PC with the person running it to make sure I didn't do anything wrong. This time, the motherboard wouldn't power on at all. Well, not quite true. We could get the Q Flash Plus to work and updated the BIOS, so there was power getting to the board. But when jumping the reset or power pins, there would be nothing. It didn't give an error code, it didn't pull power from the PSU, which was tested and seems to be working fine, it didn't do anything. I tried resetting CMOS and trying to power it on again, nothing.
And this was repeated for troubleshooting. We could always get Q Flash Plus to run where there was definitely power to the board, but the board wouldn't power on when the power or reset pins were jumped. The PC repair technician diagnosed it as "most likely" the CPU since he didn't have any spares on hand that he could test, either compatible CPUs or MBs, and because there was SOME (though not the same) problem twice with the same CPU/PSU combo and different MBs, they figured CPU as the most likely suspect.
I have never heard of a motherboard that is receiving power and can update its BIOS but that then won't do ANYTHING when you try to turn it on. And it doesn't make sense to me that it just wouldn't draw power at all because of a bad CPU. I would think it would need to draw power to know that the CPU was bad in the first place. Intel has offered a replacement unit for the CPU based on the repair technician's diagnosis, but while I'm satisfied with their willingness to try to make the problem right, I'm not satisfied with the answer that, "Oh, the CPU is probably bad." So I'm coming here to see if any of you have heard of anything like this before or have any further insight as to what might have gone wrong with both of my build attempts.
I will note, I will not have the hardware to do further troubleshooting as I'm sending the CPU back to Intel and am trying to get in touch with Gigabyte (though they haven't gotten back to me yet) and may be returning the motherboard to the vender just to go full clean slate on it and try the build again with a new manufacturer.