Hello everyone, I opened my iMac 5k 2017, I already changed to a NVMe SSD (Samsung 970 EVO Pro with the M.2 adapter) and a Crucial SATA SSD. I also upgraded my CPU for a i7700 k, After the re-assembly, my system didn’t even start, is there any step by step guide to help resolve the problem? Do I need the bootable USB drive first…? What screen should i see? Thanks for the advance !