Hunter
The 47 Ronin
Check if you installed the CPU correctly
Check all cables were attached, 4-8 pins EPS 12V to the CPU ...etc...
Unplug the new HDD and try to boot
Short pins on the PSU and check for 5V, 3.3V and 12V, see below pic
Try other Ram slots.
Check for bent pins on the CPU socket.
I think it's your mobo maybe at fault here.
Check all cables were attached, 4-8 pins EPS 12V to the CPU ...etc...
Unplug the new HDD and try to boot
Short pins on the PSU and check for 5V, 3.3V and 12V, see below pic
Try other Ram slots.
Check for bent pins on the CPU socket.
I think it's your mobo maybe at fault here.