The red led indicates a +12v supply failure.
The 6+2 connectors on some psus have the +2 section wired with +12v and gnd instead of 2 gnds as the sockets on the avalon are using.
Plugging in the pcie connectors with this type of +2 section shorts the +12v bus on the psu causing it to go into an over-current shutdown.
Just leave the +2 section of the pcie connectors unplugged, plug in the 6 pin sections and you should be good to go.
Thank you for that explanation and idea. Sadly it did not solve my problem.
I will go and purchase another PSU, hopefully that might fix the issue.
Any suggestions for a brand and model? I am not in the US but i can get most any brand that is common enough.