MacBook Pro mid 2012 freezing/crashing randomly

Most likely bad memory or a bad memory slot. A bad memory slot is most likely since the memory slot nearest the Bottom Case tends to develop cracked solder joints over time.....any pressure on the case can tend to cause the system to freeze. Try removing the memory from the slot nearest the Bottom Case to see if that solves your problem. If that memory slot is bad, there is nothing you can do other than leave it empty.

If the solder joint is cracked for the memory slot nearest the Bottom Case, then pressing on the black plastic base of the memory slot will cause the laptop to get graphical glitches on the screen or it will cause the laptop to freeze where the mouse point won't move (sometimes releasing the pressure on the base will have the laptop unfreeze, but not usually). Sometimes you can just press on the center of the Bottom Case to get the laptop to freeze, but pressing on the base of the memory slot (not on the modules themselves) is the most reliable way to reproduce the issue. When pressing the bottom case or base of memory slot, there must be a memory module installed in the slot nearest the Bottom Case.

Keep in mind it is rare for more than one memory module to fail at the same time. In fact it is rare for Apple memory to fail at all, but it does happen from time to time. I have also had the memory slot nearest the keyboard fail, but that is much more rare. Assuming the laptop doesn't freeze or get graphical glitches when pressing the base, then testing with a single memory module should reveal the bad module or slot,

You can use a bootable Memtest86 USB stick to check the memory. If you don't get any failures with the default Memtest86 settings, then try changing the Memtest86 CPU setting to "Sequential" or "Round Robin" since I have found they can sometimes report a failure (usually in the form of the test freezing...which is Ok if it only happens with one specific module or slot). The exception is test #13......the Hammer test which does not always indicate bad RAM.....if it fails the Hammer test, then you need to check to see if it actually indicates bad RAM since I recall reading that one type of Hammer test failure indicates definitely bad RAM while the other type of Hammer test failure just indicates the RAM is vulnerable to a Row Hammer attack.

I am assuming you are using the original Apple memory which shipped from the factory. If you are using third party RAM, then maybe the RAM is having a compatibility issue since Macs are very picky about the RAM used.

Hey Luddite146,

You provided some great details and information to help get to the bottom of this! From your description, it sounds like your Mac is having kernel panics. This can be caused by software or hardware, so you'll need to narrow it down using these steps: If your Mac restarted because of a problem - Apple Support

Let us know how it goes.

Take care!

Sometimes it just a bit of corrosion on the RAM contacts, sometimes cleaned by reseating a few times. :)