Isolating bad DRAM or memory bank after kernel panic

What you haven't mentioned is pressing the option key while selecting menu, which provides you with a System Information choice. Once it has launched, click on Memory and see if any RAM slot fails to show OK in its status column. If it is bad RAM, one of these may not show OK.

You could also have a outdated, or incompatible, third-party kernel extension that whenever it is requested to be dynamically loaded in the Kernel, it croaks the operating system with a kernel panic.

Put both RAM cards back in the Mac mini. Download and install EtreCheck, run it, and copy/paste its report into the Additional Text tool on the bottom of this editor. Your privacy will be protected, and it will tell us more about what you have installed on your Mac that may be causing the crashes.

Can you provide any of the Kernel Panic logs? The easiest way to locate them is by using the Console app. Within the Console app look inside the folders on the left pane which have names something like "System Reports", "Diagnostic Reports", "/private/var/log", and "/var/log", etc. When you click on the folder it will open up another pane just to the right containing log files. Look for file names beginning with "kernel" and ending in ".panic". Post all of the log files available using the "Additional Text" icon which looks like a piece of paper.

You can try running the Mini with one of the memory modules removed to see if you continue to have Kernel Panics. If you still get Kernel Panics, then try using just the other stick of memory.

You can try running longer memory tests with Memtest86 by using the older v7.5 version that allowed more than four loops to be configured. You can download the older v7.5 version here:

https://www.memtest86.com/downloads/memtest86-7.5-usb.zip

Try running DriveDx to check the health of the hard drive. Post the report here using the "Additional Text" icon which looks like a piece of paper.

https://binaryfruit.com/drivedx

Try running Disk Utility First Aid on the drive. Even if First Aid reports everything as good examine the details to see if there were any unfixed errors listed.

If you cannot determine what the cause is from any of these suggestions, then I would recommend making sure you have a good verified working backup, then perform a clean install of macOS by first erasing the whole physical drive before installing macOS. While testing you do not want to migrate or restore from a backup because you may bring a software/settings problem back.

crabpaws wrote:

<June 2 kernel panic.log>

Here is an older kernel panic report from when they happened frequently.

Last loaded extension references "msdos". It could be an issue with an external drive/USB stick. Disconnect all external devices to see if it stops the panics.

After I posted the attached kernel panic report in another thread, I was advised to run Rember. Rember said there was a RAM error.

I started this topic regarding identifying the bad RAM. Rember couldn't run on one stick at a time.

As advised, I ran MemTest86 on both sticks of RAM. MemTest86 said all was okay (this was after the memory sticks had been moved from one bank to the other a couple of times). Does this rule out bad RAM?

Unfortunately it does not rule out bad RAM. Diagnostic tests are a tricky thing. They aren't really useful unless they report an error. However, even if they report an error sometimes that error can be a false positive due to a bug, but it is the best we have to work with. Even if the RAM tests fail, it doesn't necessarily mean the memory is bad. The Logic Board or even the power supply (or even the surge strip or home electricity) could be at fault. You may want to make sure the power cord fits tight on the back of the Mini and you may want to try to use another electrical outlet (preferably on another circuit).

Check the Apple System Profiler as I believe @VikingOSX mentioned. There have been a few times where the System Profiler has identified bad memory. Usually the information for both memory modules should be the same.

I'm not a fan of Kingston memory, but it was working for nine years so it would appear to be compatible, but one of the modules could still have failed.

Tracking down memory issues is hard. Does Rember still fail when you run it?

It is hard to say if they are related (whether directly or indirectly related) or just a separate issue.

Personally I like to boot from a Knoppix Linux USB drive (or my own custom Linux USB drive) to test the hardware. Sometimes Knoppix will behave differently than macOS so that it may provide some clues. Plus Knoppix can run with just one of those sticks of memory installed and Knoppix has a memory test as well you can use from the command line if you want to test memory from within the OS like you did with macOS. I have found bad memory just by booting Knoppix since it loads a lot of the system into memory using RAM disks.

You can use Etcher (Mac/Windows/Linux) to create a bootable USB drive from the downloaded Knoppix .iso file. Option Boot the Knoppix USB drive and select the orange icon labeled "EFI". While Knoppix is booting the Mac may appear to be frozen on the boot picker menu so give Knoppix lots of time to finish booting.

If Rember is able to identify a bad module, then use Rember to test the computer with just a single module installed at a time and make sure to test each memory slot to make sure each stick and slot are working. If nothing fails when installing just a single module in either slot, then perhaps the issue only occurs with both modules installed (hard to say if the Logic Board or one/both of the modules are bad then).

Booting into Safe Mode may help to make macOS run a little better when testing the computer with just a single module.

Since I don't see any software issues in your EtreCheck report to cause your kernel panics it most likely means you have a hardware issue of some sort and memory or the Logic Board are the most likely causes assuming you have disconnected all external devices from the computer. The only thing else to try would be a clean install of macOS (erase drive before reinstalling macOS) and test the laptop before migrating or restoring from a backup.

You can create a bootable Memtest86 USB drive using Etcher (Mac/Windows/Linux). Use the downloaded Memtest86 .iso file as a source for Etcher. Memtest86 is a better option since it is more recent than Rember which I don't believe has been updated in years. Option Boot the Memtest86 USB drive and select the orange icon labeled "EFI". Once the memory test starts running you should be able to remove the USB drive if you want.

The reason Rember is running more slowly is because macOS is using most of the 4GB of RAM (or it could also indicate an issue with that particular memory stick).

Just try running the memory test while a single RAM module is installed. If no errors are found on one stick, then swap memory modules and test again. If you still don't find a bad memory module, then test the memory in the other memory slot in case one of the memory slots is bad.