Powmax Power Supply Tester with 24pin PSU ?

Has anyone here by chance used the Powmax Power Supply tester with a 24pin
PSU ?

http://www.powmax.com/pics/accessory/powertester.htm

I have an issue with a brand new box - all high quality components brand
new - where the system does not post - no beep codes at all, fans do not
spin, etc. It feels like PSU issue. But, I had initially used the Powmax
tester (this is the first time I've used it) and thought it passed. I now
realize it fails that test - but I am wondering if it is a valid test for a
24pin PSU. I used a 24pin to 20pin power adapter as the Powmax only
accepts 20pin coonector.
Since my main green LED was on, I thought it was a pass. But, the RED LED
is on, indidicating failure. (I had thought the RED LED was just an
indication it was on.) Further the +5v LED is not on.

However, I am wondering if the PowMax tester which has a 20 pin connector
accurately tests my PSU which has a 24pin connector and is attached to the
tester via an adapter. I am guessing it does and this indicates an error.
It would be nice if the issue is just the PSU. Has anyone here used Powmax
power tester with a 24pin PSU (via a 20pin adpater.) Does a good PSU with
24pin connector still test out as all green on the Powmax (via a 20pin
adapter) ? The powmax tester's doc and web site do not mention 24pin PSU's
at all.