About an hour ago, I stopped the test because it was hung up on the mainboard for over 12 hours. I started the test again but unchecked mainboard, to see if everything else is ok. I'm going to let it run its course. Hopefully, everything else will be ok and we can say that it's definitely the mainboard. It's been running an analysis of my cpu for over 1/2 now, so I'm starting to worry that it might be the cpu and the mainboard.
I'll give Sandra another hour or so to let it analyze the cpu. If it doesn't. I'll uncheck the cpu and start a new test and see if it gets hung up on anything else. I like to be thorough and I don't mind waiting to see a final report. I'll let you know the results when it finishes.