Sometimes, a BIOS update corrupts the CSME configuration. The system will hang for 2-5 minutes at the POST screen before booting. Using MEInfo to check for "Manufacturing Mode" or "Recovery Mode" flags, followed by FPT to re-flash a clean ME region, is the standard cure.
FPT64.exe -ME -F good_csme.bin
The Architecture and Application of Intel CSME System Tools v16 intel csme system tools v16