Dell Precision T7610 stuck in boot loop when trying to install any OS

Hi,

I am at my wit's end and would greatly appreciate any advice.

I recently got a T7610 workstation, but I can't seem to install any OS onto it. I have tried Windows 10 from CD, Windows 7 from CD, ESXi from USB media, ESXi from CD, and Citrix Xenserver from USB media. In each of these, what happens roughly is:

• the boot media is detected and the installer begins to load up
• the installer starts loading files
• as soon as the installer is done loading files, the workstation reboots and the whole process starts again (sometimes there is a flicker of what the next screen would look like, but usually not)
  • for example, in ESXi the reboot occurs right after the message 'Relocating modules and starting up the kernel'
    

I have tried/ruled out:

• Run the hardware diagnostic check accessible from the BIOS - no issues
• Bought a brand new internal HDD and...