I installed memtest86+ from the Debian stable repositories; I'm using stretch/stable. However, when I select any of its options from the boot menu, I just get a black screen.
I have not added new memory to the system; I'm planning to, however, which is why I installed the programs.
How do I debug/fix this? I'm not sure where, if anywhere, it stores its log files, and I have the same problem if I install memtest86 instead of memtest86+.