HP ProLiant ML310e Gen8 early system initialization hangs on 90%
Solution 1:
The problem is an incompatible DIMM module even though the memory module is sold from Kingston as HP compatible.
You can find at the HP SmartMemory Overview a list of compatible DIMMs
Solution 2:
You should check your KVM switch and/or keyboard and monitor.
Move the system to another location... just in case it's an issue with the devices you've connected to it. It seems basic, but it's a fair thing to try.