mac mini boot loop

Hi everyone,

I have a mac mini 2011 that is stuck in a boot loop. Basically it keeps rebooting.

I can boot to single user mode. If I try and do a regular boot it just reboots before the login prompt.

I have tried:

1) fresh install of sierra same issue

2) Reset of NVRAM

3) fix disk permissions

4) boot from external USB drive (same issue)

5) try booting from internet recovery (same issue)

6) run extended hard tests via hitting the D key during boot up... (it passes this)

7) verbose mode flashes past really really quickly..even when i record using a camera.. i see it probing USB ( I think) and then it reboots

I can boot into single user mode that seems to work.

Any suggestions what to try next?