The Mac Mini of Doom

Come with me if you will, as I delve into the absolute nightmare and rage inducing farce I endured while attempting to replace a mid-2010 Mac mini's failed Hard DIsk Drive with that of a Solid State Drive. The short version is I failed. By all means if you can't be arsed to read what amounts to a skyscraper worth of text then skip to the end; there's a handy bullet list breaking down what went on.

Anyway, the long version is I've got a Mac mini, a mid-2010 model with a 2.66GHz Core2Duo Intel Processor, 8GB of RAM, a 320GB 5200RPM 2.5" HDD and a SuperDrive. It was (if I remember correctly), the last Mac mini Apple ever made that had a dedicated graphics card, as well as an optical drive. There was also the server variant of this model that had two hard drives instead of one HDD and an optical.

So I mainly only use this Mac as a media server for use with an Apple TV. I have all the media files stored on an external USB hard drive which is considerably larger than the internal drive. Beyond the OS and the applications needed for the media server (namely just iTunes), I don't use the Mac for anything else really, and thus didn't really care about the internal HDD being relatively small by today's standards. The Mac worked fine for years; I rarely actually access it directly using a keyboard and mouse, but instead just leave it on all the time and have it go to sleep when not in use, and have it wake for network access.

This system worked well, up until last week that is, when while using it in this exact manor and copying files to it via the network, suddenly everything stopped working. Windows was kicking out errors about not being able to find it on the network, so I went to investigate and discovered the damn thing had turned itself off. That's never a good sign in my opinion; usually when computers shutdown like that all by themselves it means something catastrophic has happened. I turned it back on just to see what it did and sure enough after about 5 minutes of trying to load macOS High Sierra, the OS I'd been using on it for several years at that point, it gave up and turned off again.

My initial worry was the HDD had failed, so I booted into recovery mode using the key combination ⌥ + ⌘ + R (Option/Alt + Command + R) which downloads the latest version of macOS available for this Mac (and as you may have guessed, that's 10.13 High Sierra). With no issues evident so far so I started up Disk Utility and tried to repair the main drive, but this failed several times, apparently confirming my suspicions that the HDD had gone tits up.

With that confirmation I of course needed a new drive, and decided to buy a new SSD as a replacement. However these Mac mini's rather stupidly (in my opinion) only support SATA 2.0 on their controller, which means a maximum transfer rate of 3Gbit/s. Seeing as most if not all SSD's would be able to utilize those kind of speeds where as even a fast mechanical drive wouldn't get anywhere near it, plopping an SSD into one of these Macs would still see a massive speed improvement hence why I wasn't too miffed by this apparent bottleneck.

Even so, my justification for saying it was stupid to only have SATA 2.0 in these Macs stems from the fact that by June 2010 when this Mac mini was first released, the SATA 3.0 standard had been commercially available for just over a year, and the first consumer motherboards had already arrived seven months prior in November 2009, so by the time the Mac mini came along it was not bleeding edge technology by any stretch of the imagination. As far as I'm concerned this potentially indicates that (once again) Apple was using older chips in newer models of computers to (presumably) get rid of old stock. Or just skimp on cost, both of which they have been guilty of in the past and will continue to be in the future no doubt. Either way they didn't actually start putting SATA 3.0 controllers in their Mac's until 2011, and the Mid-2011 Mac mini released in July of that year was the first mini to have SATA 3.0 capability.

But I digress. So what SSD did I buy? A Samsung 870 Evo 500GB. Seeing as I could either get a 250GB or a 500GB (anything bigger would be overkill) I went for the larger of the two to avoid reducing the size of the original internal drive (from 320GB). I also assumed it would work OK as all these drives tend to be backwards compatible with the various SATA revisions and I couldn't see any other potential pitfalls of swapping an HDD with an SSD in this particular Mac. In fact the only Mac (of sorts) I've ever had issues with doing an HDD swap in was the old 1st Generation Apple TV, as that seemed to only like HDD's with at most 8MB of cache. I have wondered if I could negate this apparent compatibility issue by using a SSD, so perhaps I'll try it one day (I doubt it'll work though). But anyway I digress again.

The SSD showed up the other day, and I set about installing it. It's not exactly easy when you first do it, as there's quite a few Torx head screws in place (of two different sizes as well) plus a couple of hexagonal head screws (luckily I have an entire box full Hex/Allen keys). I won't bother going into detail as to what you have to do here, since there are plenty of decent guides that show you on the web. Once it's all pulled apart you have to also peel off a load of plastic crap wrapped around the actual drive which includes the SATA connector and power as well as a couple of heat sensors, and then transfer it all to the new drive.

So, after I put it all back together, I booted back into the recovery mode (using the above key combo to get the High Sierra recovery installer), and launched Disk Utility, which recognised the drive immediately and I formatted it with HFS+ otherwise known as Mac OS Extended (Journaled). I've seen plenty of suggestions around the web that say you should use APFS with SSD's in Macs. However beyond people just saying "it's better… Probably" there's really not a lot to go on with regards to the benefits. Only that HFS tends to put a lot of it's crap at the start of the file system to make it easier for HDD's to read them and so fragmentation isn't much of an issue, but since APFS is intended for use on SSD's which don't have the issue of seek times and fragmentation being an issue as such, it doesn't tend to do that. Added to which APFS isn't technically supported on versions of macOS earlier than High Sierra anyway. I mean, they apparently will work with it they just don't support it (so issues may arise).

In any case I just opted to use HFS+ because formatting the drive with APFS did some weird shit with the volumes it mounted I wasn't used to and didn't like so fuck it. After this, I started the installation. Which failed.

I was met with the a 'server could not be contacted' error, and after a quick search online, I found it was not an uncommon issue. I knew the Mac had Internet access and that was working as I'd literally just downloaded the recovery installer from the Internet. Whatever was wrong wasn't something I could be arsed to fix at the time; I've had trouble getting High Sierra to install on this Mac in the past so this new issue didn't surprise me in the slightest, but because I wanted to get the damn thing running sooner rather than later, instead of trying to fix the server problem (which as it turned out later on was quite simple), I opted to install an older version of macOS instead just so I could get the ball rolling.

To do this I restarted the Mac but this time held down ⇧ + ⌥ + ⌘ + R (Shift + Option/Alt + Command + R). This key combination also starts Internet recovery but rather than downloading the latest official version of macOS that the Mac supports (in this case High Sierra) it instead downloads the earliest version of the OS the Mac supports… Well, rather in the case of this Mac mini the earliest version Apple offers via Internet recovery, which is Mac OS X Lion (10.7). When I bought this Mac second-hand it had Lion on it, so whomever owned the Mac before me actually paid to upgrade it, so I never had issues with getting upgrades to the later macOS versions. But as it happens, the actual earliest version of Mac OS this Mac supports is OS X Snow Leopard (10.6), as that was the current OS when this Mac came out (and Lion didn't show up until 2011).

I have the Snow Leopard install DVD for this particular Mac, but I didn't want to use it as it's ridiculously old and obsolete by this point (it also barely works in regards to Internet access because of all the security root certificates having expired years ago and Apple never having updated them due to support ending for this OS in 2014). But regardless, Lion would do. So I started the installation, which unlike High Sierra, worked without issue. Well, at first I thought it did.

Shortly after starting installation, it crashed and dumped me back to the main menu. And it kept doing it, sometimes before I even managed to get passed the T&C agreement screen, sometimes within seconds of it starting the install process. I checked the log and discovered it was kicking out a lot of errors about being unable to verify various PKG files, and presumably crashing as a result.

Unable to continue on and pretty much stuck, I was forced to install Snow Leopard from the DVD. This actually worked, oddly enough, and before long I finally had an OS running on the Mac. Bare in mind that I had no problems at all doing this; the DVD booted fine, the installer worked fine, it didn't chuck out any errors and it restarted the Mac without issues and Snow Leopard booted off my SSD fine. Interestingly, I was able to update various things via Software Update, so it appears although no longer officially supported you can at least still get all the latest software updates for Snow Leopard off Apple's servers. Anyway it was all working nice and dandy, except for the Internet as I say, since most websites just didn't work when using Safari.

My next job was to try and upgrade to OS X El Capitan (10.11). You can't go straight to High Sierra from Snow Leopard unfortunately, you have to upgrade to El Capitan first and then go from that to High Sierra, which is a minor inconvenience but no matter. However since Snow Leopard can't access the Mac App Store anymore and without using a more up-to-date browser, accessing the Internet was going to be an issue. My only real option was to crack out my saved installers for El Capitan and High Sierra and stick them on a USB drive. I downloaded these two disk images a while back when Apple reissued the installers after the original version's security certificates expired and made them practically useless on new installs with the correct date set.

Keep that in mind also; I downloaded them from Apple directly and they were disk images Apple created and served. I had not tampered with them at all since downloading them; in fact I don't even think I ever mounted them until now either.

So I put these two images on a USB stick and moved them over to my Mac mini now running Snow Leopard. I mounted the El Capitan installer image, and, I discovered the installer inside this image could not be opened. It had the icon with the no entry symbol on it (which usually means it can't be run on that Mac), now I knew this was wrong so opened the installer anyway, but it wouldn't have it. It gave me an error that I'd actually never seen before:

"You can't open the application 'Install OS X El Capitan' because it may be damaged or incomplete."

Oh, wonderful. Sure enough I had a look at the image containing the High Sierra installer and it had exactly the same issue. So I was stumped. I went back to loading Internet recovery (the one that loads High Sierra), this time deciding to try and fix the issue it has with contacting a server. As I said before it turns out this was a fairly simple fix and I found the solution in this YouTube video. The guy that made it provides multiple solutions but the one I used was to open the Terminal and alter the URL in NVRAM. Once I did this the installer was finally able to contact the server and install, so I set it running. And, yep… You guessed correctly; it failed.

This time the installer just got stuck towards the end and wouldn't complete. Upon investigating the log, it appeared to be having the same issues Lion was (except it didn't crash like Lion); it kept failing to verify certain PKG files but kept trying it over and over. I was stumped yet again, unable to continue once more. My only working solution thus far was to install the once lovely and now decrepit Snow Leopard again and perhaps figure out a way to re-download El Capitan, even though Apple's website barely worked with Safari on Snow Leopard, and hope a the newly downloaded version would actually work over the one I downloaded a few years ago and stuck in storage. However before that I had a look online for answers as to why exactly Lion and High Sierra were suffering with issues verifying the PKG files in the first place, since that to me sounded sinisterly like the SSD I put in the Mac wasn't working properly, or the OS wasn't working properly with the SSD. Either way that would have been a disaster, all be it not an entirely surprising one.

I did come across a couple of people suggesting something odd though; if you had two RAM modules installed, take out one and try it again with just one in place. Now, I upgraded this Mac when I bought it with two brand new sticks of 4GB DDR3 that I sourced from Crucial, and they've worked fine ever since. I couldn't understand the logic behind why taking one module out might make the installers actually verify the packages correctly, when I've had these RAM modules in that Mac for years and never had this issue before. But I figured I had nothing to lose, so I tried it. I took out the first RAM module (the top one), and turned the Mac on to try install macOS again and… It beeped at me.

Now I forget what combination of beeps I had, but given I'd just taken the RAM module out I thought it was fairly obvious what was going on here; it seemingly worked with two modules but not with just one? Must be bad RAM! Or, worse, a bad slot. So first I moved the module still in the Mac to the second slot, and thankfully it still beeped at me and wouldn't boot. So I took out that module and put the other one back in and… The Mac booted. So yes after all that I had not only suffered with a failing/failed HDD but apparently one of the memory modules had gone bad too.

So with supposed duff memory module out of the Mac mini I tried to install High Sierra once again, and bugger me sideways, it worked! Sort of. After completing the initial installation it rebooted. Then as it began to load to finalize the installation, it seemed to stall briefly before it left me confused once again by popping up with a sodding no entry symbol:

Apple's official explanation for this "no entry" or as they call it the "prohibitory" symbol on boot is that, although it found a version of macOS on the startup disc, it's not a version the Mac can use. This of course makes about as much sense as a shit with a wig winning the Miss Universe competition, because I was installing High Sierra; the version of macOS Apple states is the last officially supported version for this Mac, and indeed is the version of macOS I'd been using on this Mac mini for several years by the time the HDD went down the shitter.

I immediately just chalked this down to High Sierra being a bane of my existence because as I mentioned previously I've had issues getting it to upgrade to 10.13 in the past, so, fuck it. I went back to Internet recovery and this time installed Lion. I was able to install it this time and had no more verification errors with PKG's and it didn't crash, so "clearly" the RAM module was definitely the issue there (I thought). Anyway It seemed to finish installing just like High Sierra did, restarted the Mac and… I got the "no entry" symbol again.

At this point I was just about ready to grab the smug little bastard and throw the fucker out the window.

So back to Snow Leopard I go only this time I went looking for a new download of El Capitan using my Windows PC instead, which I found quickly as Apple actually do provide links to various versions of the OS using a web browser (so what I needed) here.. Unfortunately they only let you download up to Sierra (i.e. the one prior to High Sierra) via a web browser. If you want High Sierra you still need to get it from the Mac App Store, but only by using a link on that page I linked to, as you can't find it manually by searching for it in the store. This didn't bother me too much as I just wanted to try and install El Capitan over Snow Leopard, and then I could update to High Sierra using that method.

So I install Snow Leopard. Again. And I transfer the newly downloaded El Capitan installer via USB to the now booted Mac. And with baited breath I open the disk image. Success! The El Capitan installer isn't crossed out like it was before, so I run it, and it installed El Capitan over Snow Leopard. Finally. It restarts the Mac and… It pops up with that fucking "no entry" symbol again!

To say I was livid is an understatement.

However, Apple suggests if you see this symbol that you turn off the Mac by holding down the power button for ten or so seconds then boot into recovery again, but I had a hunch. I turned it off using this method, just like I'd done previously many times over the course of this farce, but this time, I just turned it back on and left it alone without booting it into recovery. I wanted to see if maybe it was some sort of quirk of having an SSD in it, or maybe I actually had two bad RAM modules, just that the one in the machine wasn't quite as borked as the other one I'd taken out. After a minute of apparently no activity, suddenly an Apple logo appeared, then a status bar appeared under that and finally the text telling me it was completing the install popped up.

After a while, the El Capitan desktop showed up. So it turned out that all I had to do to get past the "no entry" symbol was to just restart the Mac again with a hard reboot and let it carry on. Intrigued (and thoroughly irritated) as to why it did this at all though, I ordered two new sticks of RAM. I decided not to bother just buying one stick in case both the existing modules were in fact bad and not just one. I also decided not to pay through the nose for them and ended up just buying a couple of Samsung modules going cheap on Amazon of all places that matched the specifications of the Mac mini. I didn't want to revert to only have 4GB in the machine anyway so I was always likely to get more RAM for it to bump it back to 8GB so I might as well do it now rather than later, no?

Of course, being DDR3 memory, these days you can't really get top quality RAM modules in that format anymore. DDR3 hasn't been sold by any of the top brands in several years. Not even Crucial, my original supplier of the supposed duff RAM modules, sell it now. So it was a case of either buy cheap generic crap, made from surplus stock and probably just as likely if not more likely to fail, or buy second hand modules also with no guarantee they'll last, or at least find some old "new" stock from a reputable brand which is what I ended up doing (because there's no way Samsung have made these modules recently as they apparently ceased production of DDR3 chips at the end of 2022).

After a short wait the new RAM showed up on my doorstep so I went ahead and plugged it in fully expecting my issues relating to that to be fixed. Oh how wrong I was. With both modules inserted I powered up the Mac and the fucker beeped at me again. This time, different to the previous set of beeps, it just beeped, steadily, and continuously every few seconds. I mean, clearly this was because of the RAM so I took the modules out and swapped them around, I also made sure they were seated correctly. But alas, it continued to beep like R2D2 on dope, so a quick search online found me Apple's beeping Mac support article again, and this time it suggested a Mac beeping every five seconds meant it couldn't find any RAM when it booted.

Couldn't find any? Doth my eyes deceive me? Have I put in two imaginary sticks of RAM or something? Maybe I accidentally ordered a fucking stick of butter and squished that in there instead? No, I had in fact put two sticks of supposedly compatible RAM in the Mac but it refused to believe it. So on a whim I took one module out, and left the other one in, and this time, the cunt booted! I proceeded to assume therefore seeing as I'd taken the top module out (or rather the one furthest from the logic board) that this slot must simply be bad, but was it really? So I swapped the one module I'd left in into the other slot. The Mac still booted.

So, as best I could fathom at this point, and to recap overall what had happened:

• I'd put a Samsung 870 EVO in the Mac. The Mac could apparently see and read/write to it without any issues (looks can be deceiving).
• One of the Crucial RAM sticks seemed to be bad, as with both inserted I got verification errors or installer crashes and these went away when I took one out.
• Both the new RAM modules worked, just only one at a time, in either slot, indicating I didn't have a bad slot either.

At this point I started to wonder something. Was the Crucial memory stick truly bad? I decided to put the Crucial memory stick I thought was fluffed, back in the Mac, on it's own, but this time in the upper/top module slot. Prior to getting the new RAM I'd had the supposed working Crucial stick in the lower slot and got rid of the verification errors in doing so, hence why I thought the other stick or slot was buggered. Well wouldn't you know it only went and ran fine like that as well…

In all honesty at this point I was completely up shit creek without a paddle. Luckily for me I could send the new RAM back for a refund because there was apparently no using that given I couldn't put both in the Mac without it beeping, but it seemed like the Crucial RAM it replaced wasn't borked in the first place. Neither were the slots on the logic board either, so why the Mac beeped at me the first time I have no idea. It all just seemed like these issues, bar perhaps the one with the URL and High Sierra, all happened after I put that poxy SSD in the Mac. The question on my lips now was, what would happen if, for instance, I stuck an HDD in it instead? It just so happened I had a 500GB Western Digital Black drive that I didn't really use much and that might come in handy as a test.

If I put that HDD in the Mac mini and put both sticks of Crucial RAM back in it and then booted High Sierra's installer and I didn't get any verification errors or that prohibitory symbol, well, then I'd know what the culprit was all along. But first things first I wanted a bootable USB of High SIerra as I didn't feel like messing around altering the URL of the Internet Recovery version (since I planned on resetting the NVRAM before beginning anew with the HDD in place). Before removing the SSD, and having taken out yet again one stick of RAM, I installed High Sierra via Internet Recovery, and after rebooting at the prohibitory symbol to get it to install, I had High Sierra running. I mean I could have just called it a day there but I wanted 8GB of RAM and didn't trust that putting the second stick in after it was installed wouldn't cause issues, so I carried on with my plan. Besides I wanted to know if the SSD was in fact the problem.

So I downloaded and created a bootable High Sierra installer as per Apple's instructions, then turned it off. Went through the trouble of swapping the SSD with the HDD, put both sticks of Crucial RAM back in it and booted it (resetting the NVRAM in the process so I could have a clean slate), and then letting it boot from my newly created High Sierra USB stick.

It booted fine. I installed High Sierra and got no verification errors. It restarted and carried on installing and I didn't get a prohibitory symbol.

At this point, I thought the SSD's fate was sealed. It was going back for a refund, as honestly I had no need for it (not even to replace the HDD I'd replaced it with in the external enclosure as I barely used that for anything). But it's left me with somewhat of a burning question I cannot find an answer to: Why?!

However, while all this was swirling around in my fat head, the High Sierra installation popped up a vague error about how it couldn't install and that I could run Apple Service Diagnostics by holding down "D" on the keyboard when starting the Mac up. Oh joy, my problems were not over. Now, High Sierra has actually given me this error before when I've tried to clean install it on this Mac mini even when it was all working as expected so I wasn't totally disheartened by this message. I figured I'll install Snow Leopard or Lion instead. So I tried Lion next, and then I did get disheartened when that also failed. This time with similar verification errors it was having right at the start (although it didn't crash this time and only had one verification error with the Installation DMG image and not any PKG files). Fine, I opted to install Snow Leopard from the DVD again! And all was going well until it too failed with a big arse error message saying it couldn't copy the necessary support files.

Well shit.

I once again resorted to pulling out one stick of RAM, and once again tried installing High Sierra from the bootable USB. This time, it worked. As such, it would in fact appear that I do have bad RAM. Or was it the slot? I didn't know. I'd actually forgotten which module it was that resulted in a beeping Mac, and currently I had a module in the lower slot only. Perhaps it was time to try some more technical testing approaches: Apple Service Diagnostics.

This tool might give me some kind of idea as to what's going on after all. But as per what seems to have become the norm with this Mac, after rebooting and holding "D" to get it to load ASD, it spent a great deal of time downloading something, then when ASD finally loaded it immediately told me that the version that loaded was not compatible with my Mac mini and I could go fuck myself… Only Apple would provide an Apple Service Diagnostic tool for a Mac that it doesn't support. I did have a look online and it seems the tool version I require, of which Apple clearly doesn't furnish you with via the online system they have, is 3S139. And no I couldn't find a download for it. Or rather a download that either worked or didn't require I fork out money for, so I gave up with that venture.

Instead I went the MemTest86 route; created a bootable USB of that and booted the Mac with it and began running the default set of tests, which is all of them bar one labeled as experimental. Keep in mind I still only had one stick of Crucial RAM in the lower (i.e. closest to the logic board) slot. MemTest86 did its thing, then it got to Test 9 and promptly froze. The test up to this point had not reported any errors, so I restarted the Mac and deselected all the tests up to 9 and started again so it could continue where it left off. It crashed again shortly after, and by crashed I mean the entire program locked up solid and I had to force shutdown the Mac.

I took the Mac's arse off and removed the module from the lower slot and put in the other module in the same slot, I figured if it also crashes at Test 9 maybe I am indeed seeing a failure of the slot rather than the memory. Except when I turned it back on it started beeping at me again. Turns out (since I'd forgotten before what beep pattern it had given me the first time) that it was beeping 3 short beeps, 3 long beeps, and then another 3 short beeps. Apple says this is a firmware issue and that my Mac is resolving this and that I may see a progress bar before it continues, but nothing like that happened no matter how long I left it running. So after a while I couldn't be bothered to wait any longer for it to resolve any issues, if it even would be able to, and after turning it off I took the RAM out of the lower slot and put it in the upper slot. The Mac still beeped at me in the same pattern when turned on.

So I turned it off again, removed the RAM module and put the other one that apparently worked back in, only this time in the upper slot. I figured that if the working module crashes at test 9 in the upper slot then it's surly got to be the RAM and not the slots that's at fault. Either that or a fault on the logic board. So I ran MemTest86 again from the start. Annoyingly it went through an entire test pass without issue, although then on the second pass, at Test 7, MemTest crashed again. I wondered if I put the dud module back in on it's own in the upper slot, maybe it'd boot (just on a whim), because I couldn't test it if the Mac wouldn't boot after all. Oddly enough, my sixth sense paid off and it did in fact boot this time, with no beeps. I let it load into macOS rather than MemTest86 accidentally, and within a minute before I could restart it the Mac shut itself off and beeped again.

I tried putting the two Samsung memory modules back in to see if anything had changed there, but it still refused to boot at all with both of them in place. So it was at this point, I gave up. Whatever is wrong with this Mac stems much further than just a simple incompatibility issue with an SSD. It seems as though that, the HDD failed completely, but apparently so did both RAM modules but perhaps also the slots and maybe also the memory controller on the logic board itself has gone tits up. I've never seen such a massive cascade failure in a computer like this before, and I have literally no idea how it happened or why it seemed to happen so suddenly.

In the grand scheme of things I can essentially narrow it all down to:

• The new SSD works, but is apparently causing the Mac to show the prohibited symbol on first reboot after installation of macOS.
• Both the old Crucial RAM modules seem to be suffering from failure, one more so than the other as it can prevent the Mac booting in most instances.
• Completely different and supposedly brand new (all be it old new) compatible RAM modules will only work in the Mac one at a time.
• There could also be an issue with either one or both memory slots or the memory controller and by extension the logic board.

How could all this happen in such a short space of time? My only guess is leaving the Mac switched on (but letting it sleep when not in use) has apparently contributed. Either that or the fact a few weeks ago I did accidentally unplug the Mac while I was fiddling around behind the cabinet it is situated in. I turned it back on shortly after and booted it (it's set to automatically log into my user account so I don't need access to it). I didn't actually check to see if any errors had popped up after doing this so it could very well be the catalyst that set in motion these apparent multiple failures. Of course, it could also all just be one gigantic coincidence, but part of me thinks all of these issues are very much linked one way or another.

At the end of the day, all this started when the HDD failed. Me putting an SSD that apparently suffers compatibility issues with the Mac probably wasn't the main problem after all and instead acted like a gigantic red herring that mislead me for a lot of the time. But that's not to say the SSD didn't cause any problems at all; it clearly was responsible for the prohibited symbol on reboot of a new installation. That's an issue I may not solve. Although an SSD is fundamentally different in architecture to a mechanical drive, if they're both sporting a SATA connection then they both use the same backwards compatible SATA interface, so one would assume they will work as expected when connected to a SATA controller in a computer regardless of the revision used due to the backwards compatibility. But this is evidently not the case.

It would appear not all SSD's are created equally, or rather their controllers aren't. Although I can't say for certain why I have issues with this SSD, I can say for certain that whatever the problem is, it's because the controller in the SSD doesn't play nice with the SATA controller in the Mac. I've actually read of this happening to people before, not just with Macs but bog standard PC's as well. SSD manufacturers also have this nasty habit of "upgrading" their SSD's with new controller chips as well as altering the NAND configuration (MLC, TLC etc.) but keeping the model names and numbers the same, so while one particular model of SSD made on one particular date might work fine, the same model made at a later date may not for this very reason.

I could perhaps investigate to see if updating its firmware (as there does appear to be Mac specific firmware for this particular SSD) would solve the issue with the prohibited symbol on boot, but that is only an apparent minor inconvenience compared to the fact the memory modules appear to be causing widespread corruption and other shenanigans.

Ultimately my only choices would be to buy new RAM, again, and see if that works, or bite the bullet and buy a new logic board for the Mac. But the fact is I can in fact just get an entire replacement Mac mini of exactly the same model and specification, guaranteed to work fine and all for a little more than a second hand logic board. So that's exactly what I did.

The "new" Mac arrived with 8GB of RAM like mine had, in the form of 2x4GB Kingston modules. Before I started buying RAM from Crucial, I used to buy Kingston RAM all the time so I was happy with this. The replacement mini also had an 256GB SSD installed which turned out to be a Samsung 850 Pro (so not too shabby, but I am always highly cautious of using second hand SSD's). My first instinct with it though was to swap the 850 PRO SSD with my new 870 EVO and try and get an OS on that just to see if it still suffered with the prohibitory symbol issue after reboots.

It did.

So that ruled out the actual Mac being the culprit (even though it clearly had other issues with RAM). As such, I then tried the firmware update route for the SSD. Now, I didn't know exactly if I was correct in the assumption that there was Mac specific firmware available for it. Normally of course Samsung just recommends you download their bloated Magician software to both keep an eye on and also update the firmware of an SSD, but they do in fact have a web page that lists all their SSD's latest firmwares with download links to an ISO image for them. The page clearly shows the 870 EVO as having two firmware images, a normal one and one below that labeled "SATA SSD-870 EVO Firmware for Mac" with no mention as to what it means by this. However this does indeed appear to just be referencing an image that can boot on a Mac and update the firmware, while the actual firmware itself is apparently identical in both images.

I found this out because I downloaded the Mac version of the firmware image, burned it to a CD-R and used it to boot the Mac (it did boot too with no extra steps as the image contains a bootable Linux distro as best I can tell). Once booted I just followed the prompts, hoping that it was going to reflash the firmware with a Mac compatible version, but instead it ended with it simply saying the SSD firmware was already up to date. So that was the end of my time with this SSD, and my conclusion is, as has been fairly obvious from the get go, that it isn't fully compatible with older Macs. Maybe people with newer (much newer I'd wager) Macs might have some luck with it but even then I wouldn't risk it.

On that same page as the firmware images, underneath both of the ones for this 870 EVO SSD, it states "The 870 EVO model will be manufactured with a revised V6 process starting November 2022" - This had me looking the SSD up to find out what this actually meant, and I was surprised to find the 870 EVO had become quite notorious after its release for being prone to problems and premature failures. I genuinely didn't bother looking up opinions and reviews on this SSD before I bought it, as I've always considered Samsung's SSD's (even the EVO models) to be some of the best available. Looks like I was wrong.

Anyway thankfully I bought it from Amazon so had the luxury of their 30 day refund policy. Personally, I'll probably not bother with Samsung SSD's ever again as a result of this, at least not the EVO models. Not that it matters much, seeing as they seem to have stepped away from providing models in the 2.5" SATA form factor anyway, which currently is all I tend to have a use for.

After all this though I was still a bit miffed that I either had to now use a smaller SSD (all be it an apparently compatible one), that came with the replacement computer, or just not use an SSD at all and carry on with a traditional HDD. Fuck that, I wanted an SSD in this Mac, I wanted a 500GB SSD at that, and I wanted one that actually fucking worked properly. However trying to find a new 850 (or at a push an 860) Samsung on eBay seemed rather expensive and there was no telling they were actually new like stated, or even real for that matter (given fakes are rife on these auction sites).

So I searched again for a compatible SSD of any brand via Google just to see what I came up with. And what do you know, Crucial once again popped up in my results. Their own website no less states that both their MX500 and BX500 are compatible with the mid-2010 Mac mini. I've never bothered with Crucial SSD's before even though I tend to only buy RAM from them, simply because as stated above I had always assumed Samsung to be a maker of top-tier SSD's so why bother with anything else? Indeed, Samsung's 870 EVO apparently does outperform Crucial's MX500 in various areas, but of course, with this Mac being SATA 2.0, it didn't matter did it? Even a slower SSD would still be faster than the SATA 2.0 connection could handle.

Of course there are other factors involved when you start talking about SSD performance, such as how well it can read/write large files, and how much it slows down over time the fuller it gets. But again, this Mac isn't a daily driver; all it does is serve media from an external HDD. So who gives a fuck about SSD performance? I just want to know if it bloody works (i.e. doesn't cause the prohibited symbol). So, after refunding the Samsung and sending it back, I bought an MX500. But when it arrived a couple of days later I had an idea: Instead of putting it in the replacement Mac, I would put it in my original mini, and I would stick the Kingston RAM modules from the replacement in there too. After all, this was a perfect way to test it and kill two birds with one stone; If it booted, installed macOS without errors and also didn't show the prohibited symbol on a reboot, not only would I apparently have solved the issue about the SSD but also figured out that the RAM itself was definitely what caused the other errors and not a bad logic board or RAM slots.

So I did. And it worked!

After all this faffing around, all this bumbling in the dark and being in denial that a brand spanking new Samsung SSD could be causing incompatibility issues, and not only that also being in denial that the Crucial RAM I'd bought several years ago had gone bad somehow, I finally had an answer. The Samsung SSD is definitely not compatible with these old Macs. And the Crucial RAM had gone bad. Not only that but it also proved the replacement Samsung RAM I bought was probably also bad or at least not quite compatible enough with this old Mac despite it's specifications. Which, when you consider the fact it was Samsung branded RAM, maybe that isn't so surprising given the trouble I just had with one of their SSD's.

So to sum it all up, in the end;

• Initially, the Mac mini's 320GB HDD had failed… Hard (completely unrecoverable and with total data loss).
• At the same time, the RAM had gone bad, causing boot issues as well as installation errors, although I only found this out after replacing the HDD.
• The replacement SSD, a Samung 870 EVO, with the latest firmware, was not fully compatible with this Mac (and likely never will be).
• After figuring out the RAM had gone bad, I discovered the cheap replacement Samsung branded RAM I ended up buying was also apparently not fully compatible with this Mac.
• Nothing I did beyond replacing these components could rectify any of the issues; reboots, SMC resets, NVRAM resets and countless wipes and reinstalls using Internet Recovery as well as bootable media. Nothing worked.

It does seem a bit like an unfortunate coincidence that the HDD failed and at the same time, so did the RAM. This made it seem like there was more wrong than there actually was; what really didn't help was when I replaced the RAM with supposed compatible spec modules and they didn't work properly either, as it essentially lead me on a wild goose chase thinking maybe the RAM slots or something else on the logic board was kaput, when in reality I'd just bought what was probably cheap generic crap RAM with fake Samsung branding (although Amazon delivered it via Prime fulfillment, they weren't the seller).

Ultimately the takeaway from all this is you shouldn't automatically assume any SSD or any RAM module (even if it's the right specification) will work in one of these Macs. I did, and look at the hassle I went through rectifying the problem! And lastly, you may ask about that replacement Mac mini I bought. Well, it was essentially cheap given it gave me two good RAM modules and a decent 850 PRO SSD, and now I have a spare mini for parts, so, all is well that ends well I guess? But by thunder was it an uphill struggle getting here…

Mac-mini Upgrades SSD Clusterfuck