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#11
I wanted to report back that my issue was finally resolved, and I believe you were right that it was a faulty motherboard.
I replaced the motherboard and I actually had the same issue at first. Then I replaced the RAM (again) and the problem vanished. I believe the original motherboard was faulty and was damaging the RAM, which would explain both a) why replacing the RAM that had been used with the original motherboard solved the issue and b) how I managed to get bad RAM several times in a row!
Thank you to all who took the time to help me. Very, very much appreciated. This forum is an invaluable resource!