So here's how my piece of shit Mac keeps crashing lately

Every few days, the UI locks up: the mouse still moves, but the menubar clock stops counting seconds, and the screen never changes. However, all apps are still running. Music still plays. I can ssh in.

I've run the "hold down D at boot" hardware diagnostic, but it completes quickly so clearly it doesn't test much. I also ran memtester, and it found no problems.

So is this, "Oh yeah, 10.14.6 just does that shit sometimes" or is it, "you need to taxi this thousand pound piece of shit into the shop to have its skull scooped out with a rusty spoon"?

Also it there some process I can ssh in and kill that will drop the Mac back to "log out and re-initialize the graphics subsystem", slightly less extreme than rebooting?

It's an iMac Pro 2017 8 core, in case that is relevant.


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25 Responses:

  1. Chris Hanson says:

    You can kill loginwindow and get back to a new login window, it’s effectively the session manager for graphical logins whether via console or Screen Sharing.

  2. Dirk Steins says:

    I'm running also 10.4.6, but on a nearly 4 year old MBPro. No problems in that direction here, so I don't think it's a problem of Mojave. Not helping very much, I know, just wanted to let you know.

  3. robertklep says:

    Try running something to stress the GPU, might be an issue with solder connections when it heats up (I think the remedy for that would be a reflow).

    • Torkell says:

      It's possible to fix bad solder joints by baking the board/card/whatever in an ordinary oven! How long the fix last varies - a GeForce 8800GT that I managed to repair by cooking for 10 minutes at 200°C lasted another 4 months or so before failing again.

  4. Mark says:

    No solution to offer, but “10.14.6 just does that shit sometimes” for me too, so maybe not a hardware thing...

  5. Jackson says:

    That happened to me a few days ago, and did in older versions. I unplugged a malfunctioning external drive dock and everything snapped back to normal. I'd say look at your logs but console is so noisy these days it might be fruitless.

  6. Michael says:

    Has happened to me as well a few times. Seems not be hardware related. I can move the mouse around but keyboard input and mouse input aren’t registering. I found that unplugging / turning off the offending device(s) and then reconnecting seems to fix it.

  7. Unxmaal says:

    Issue segmentation:
    * Make a new user jwz2. Log out of jwz. Use it for a bit. If trouble persists, it's likely hardware. If not, there's something busted in ~/Library, bad app, bad app update, etc etc.

    * Detach all attached USB/Firewire/FDDI things. Frog USB mouse/kb to currently unused ports. If issue persists try swapping mouse/kb for other mouse/kb.

    * Clean hardware. Giant blower, pull cards, clean pins, reassemble.

    * Attach external drive. Install Catalina on external drive. Boot from it. Do some stuff.

    If problem persists after this last step, throw it out and get another one.

    (You could also try installing Mojave on that external hdd, but by this point it's pretty much determined to be infested with demons.)

  8. neil says:

    This exact behavior started happening on my iMac running 10.14 about two or three months ago. Eventually I noticed that it corresponded with an app pegging my GPU for a long time, usually an electron app or chromium browser (for me, Slack is the biggest offender). Turning off GPU acceleration in these apps does not seem to help.

    I have no idea what actually happens, but it seems like some part of the GPU turns itself off due to heat, and the GPU kext and/or userland are not notified about this.

    Activity Monitor has a GPU graph, I keep that on in a corner of my display and glance at it once in a while, and if the GPU has been pegged for a while, I kill whatever app seems to be causing that. This has prevented the problem for me.

    • Derpatron9000 says:

      Slack is the biggest offender

      It's 2020, chat programs are killing computers, what a world we built...

      • neil says:

        Slack is much more than a textual conveyance, but ok.

        • jwz says:

          Dude, it's IRC with fonts and the IMG tag.

          Computers are how many orders of magnitude faster, and you're still managing to peg them with that weak shit?

          • Netabuse says:

            Dude, it's IRC with fonts and the IMG tag And installable apps that mine your precious personal life for salable nuggets of information. Very good for the shareholders.

            Also, this used to happen to me in 10.13[?]. The way I fixed it was reinstalling MacOS on top of itself. YMMV.

          • neil says:

            I'm not making a commercial for Slack here, but Slack is much closer to Skype than IRC. I use it mostly for screen sharing and audio/video and "private twitter". I use it for my job. The Slack app itself is an abomination, especially in its IRCness. If I could use `talk` for text I probably would.

            But since this iMac-freezing behavior seems to happen with electron apps as well as chromium browsers, I'm assuming it has nothing to do with Slack, that's just the way it manifests for me, and I thought it would be helpful to say so. Sorry.

            Seems like a bug in macOS that is triggered by chromium/V8/whatever, that's all I'm saying.

            You do you.

            I would also like to know how to recover from this form of a frozen iMac. kill -9ing `loginwindow` and `WindowServer` does not work.

        • Derpatron9000 says:

          It's essentially a bloatware clusterfuck reinvention of IRC with some bells and whistles that make it more annoying, while exclusivity storing all the data on their private clown.

          • Mark Crane says:

            I can't find the link but someone wrote that everything from the early days of the internet, like IRC, has been commodified.

    • jwz says:

      Well, you'd think that xscreensaver would be the biggest GPU stress-test possible -- and yet this crash has never happened while the screen saver was active. In fact it may only have happened when I was doing something totally innocuous like scrolling in a browser or Tweetdeck.

    • jwz says:

      Well I left the Activity Monitor GPU graph up for several days, and it rarely showed anything, and never pegged it, even when running screen savers or transcoding video. And it had been blank for a long time the last time the Mac did this stupid thing.

      This time I logged in remotely and was able to power off the monitor using pmset. I waited a few minutes then touched the keyboard, and the monitor powered back on but stayed black. So that didn't help either.

  9. Carlos says:

    OSX 10.14.6 runs more or less stably for me. I had to reboot an oldish MBP yesterday at 61 days uptime, but it had not had any problems like you describe in that time.

    re: Slack - indeed, it's IRC. They even had to disable their IRC-to-Slack gateway because too damned many old-timers were using it. Can't have that.


  10. rps1227 says:

    Similar thing used to happen with my MBPro (on various 10.14 but not recently on 10.14.6). Putting it to sleep and waking it would quite often fix it.

  11. Legolas says:

    I don't have the problem, so I can only offer ideas... Hopefully they can inspire a workaround.

    Any chance of trying via ssl things that would do something with enough impact on the GPU/display to clear whatever seems to be stuck? I'm thinking about changing resolution, or run some full-screen app (that takes the screen into some full-screen mode like games do? Maybe a screensaver you have already does that? at a different resolution than the normal one for full effect?)

    And then of course for the full monty, automate this to detect the problem (screengrab the clock area and see it doesn't change every second?) and auto-fix it! ;)

    Meh that you have to do this though :(

  12. Zach Fine says:

    I had all sorts of interesting problems happen in macOS with intermittent, incomplete, indeterminate crashes when I had a failing external USB hard drive connected via USB. Since I disconnected it (and other external USB drives except when in use) my system's stability has gotten back to months of useful uptime.

  13. Rich Holland says:

    Have you tried resetting the SMC and NVRAM / PRAM? I always do both at the same time (big hammer). Power cycle it and then press Control-Option-rightShift for >= 7 seconds, then while continuing to hold them all down, press and hold the POWER and hold all four keys for >= 7 seconds. Wait a few seconds and hit POWER to turn on. Immediately press and hold Option-Command-P-R (4 keys) and hold together. You'll hear a bong and it will reset again. After the 2nd bong, let go and it should boot up normally.

    Here are some official apple links on the reset procedures; they may vary for your hardware:

    SMC -

    I do that anytime I get weird hardware issues with my MBP, and it usually seems to fix them (for some random period of time).

  14. jwz says:

    For those of you following along at home (and why would you be) it's still doing this about once a week. But, yesterday I was doing some editing in iMovie and over the course of a couple of hours I had to power-cycle the machine like four times.

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