I am sorry to hear you are having problems but let me help you.
There are some questions I would like to ask you to know about your system configuration but have you tried a different memory stick? Maybe different brand and model? Have you tested a different software to do the memtest?
As i wrote, i used a CD to boot up Opensuse. I have installed a Samsung 2,5" Sata HDD. The same behavior appears, when booting the system with a Openmediavault-CD 0.5.0.24 x64 . The system freezes completey only 2 seconds, after bios has executed basic boot procedures on the cd. My RAM is OK. I ran several heavy load test through hours, and everything was stable. The USB-CD-Drive is an Samung SE-208 and directly connected to the front USB. Very old versions of Memtest are running fine, but they do not recognise Board and CPU correctly of course
I am not sure what BIOS version you have but in any case here you can download the latest one:
You mention that you’re using a live CD but what happens if the Operating System is installed?