iMac 27 inch late 2013 Kubuntu 20.04 update problems
 

Greetings,

Let me start by saying I tried to search for iMac and Mac here in the Ubuntu forum, but got a database error page each time.

I have rescued a late 2013 iMac 27 inch from work and have installed Kubuntu 20.04 on it successfully. Everything works 'out of the box.' I did select to install proprietary 3rd party drivers during install.

I configure my wireless network connection and Diskover finds updates available. I update and reboot, only to be greeted with a ShimX64/grubx64 issue.. easy enough to fix after a brief search... but even after fixing that (and when it boots through the error anyway) the wireless adapter, the sound device, Bluetooth are all missing. I can see (in the Hardware Drivers 'Additional drivers' tab) that nVidia drivers are loaded and that Broadcom drivers are loaded, but the sound and network status icons show red dots/indicators. The Broadcom drivers do have "(open source)" at the end of the name.

Why would a system update BREAK things which work after the original install? (Okay, dumb question...). WHAT is the update doing which is breaking drivers which work after the original install?

I'm new to running Linux on a Mac, and it may be something that's been dealt with many times over, so I apologise if I haven't managed to find the correct search terms.

Can anyone help with some tips on how to avoid system update packages trashing the working drivers?

Been happening for searches here for a bit; if you wait and reload the page, it'll often come up.
I can tell you that I'm running openSUSE Tumbleweed, so I can't speak directly to Kubuntu. But I CAN tell you that Apple hardware can be touchy, especially when it comes to another operating system. Some things here to note:
https://www.linuxquestions.org/quest...9/#post6041239

The iMac bluetooth adapter is a separate device (upper-left corner of the machine, if I remember correctly). It may have a Broadcom chipset, but it is most definitely modified by Apple. Same with the wifi adapter (their 'Airport' things). I personally like the form-factor of my iMac, but have tweaked it a good bit, if you see the post I linked to. The Apple bluetooth device will vary on/off a LOT, and your bluetooth devices will 'pause' in the middle of use a good bit. Wifi range and speed stinks as well. If you want to use this machine, I'd strongly suggest spending a few $$ and a couple of hours, and upgrading things.

The wifi card is a standard PCIe card. I ordered one like this:
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

...but there's probably a newer version. Updated my bluetooth and wifi at once....wouldn't work under OSX, but Linux had zero problems. Same with the memory cap; was able to use more than OSX said you could in the machine. Throw in an SSD to speed it up and a temp sensor to keep the fans running well, and you'd be in good shape. Again, I run Tumbleweed and have had ZERO issues with any updates, but I'd start by addressing the questionable Mac hardware first.

I'd really like to just update my system and NOT have to buy extra hardware as the installer can get it working. Maybe I can ask on a more Ubuntu-oriented forum.

Someone may answer you here, but is there a reason you don't want to try a different distro that may just work, or why you want to stick with a *Buntu?

And as said, no matter what distro you pick...Apple hardware can be twitchy with ANYTHING that's not Apple. If you want to try to work through the problems, then post some relevant information from the system logs/dmesg/etc., along with anything you tried. We can't help you work through a problem unless we know what it is.

And since you said it was working initially, try a re-install except this time without selecting the third-party drivers, and see what you get. And the only reason I suggest a hardware fix, is to remove the limitations of the iMac. You'll be able to get better wifi speed, updated bluetooth, and a faster SSD (which also drops the heat in your system, too). And instead of the $$$$ the 'Apple approved' hardware would cost, you could do everything for a LOT less.

He is failing to understand what you try to tell him. His mind is set on the idea that this will work because he had limited success, until your point becomes clear. The changes Apple have made to the hardware are always going to come back to bite you on the bum. With the exact problems he describes attributable to said hardware and its flaky incompatibilities.