iMac i7 random hanging

Discussion in 'iMac' started by c84216, Apr 26, 2010.

  1. c84216 macrumors member

    Jul 15, 2006
    Good evening. I have a question for you all.

    Recetnly, my iMac 27" i7 has begun hanging in the most bizarre fashion.

    It usually seems to happen when I wake the computer from sleep or screen saver, but that isn't always the case.

    What will happen is that when I get to the computer, Mail will show symbology that indicates it is not connected to the Internet or Safari, upon booting, will not open a webpage (it sits on a white screen rather than delivering an error). I'll go to quit one of the offending programs, and it will not quit and beach balls instead. I then right click on the dock to trigger a force quit, and the force quit does nothing and the dock beachballs. I try to restart/shut down, and nothing happens. Thus I am forced to hard restart.

    Conversely, I am sometimes able to get an offending program to force quit, but the rest of the computer (anything I click locks up) beachballs leaving me to hard restart. I find when this happens, my first instinct is to click system prefs and go to networking, where when I click networking, it locks up. Then I have to hard restart

    Finally, there are times when it does respond to a restart request. It will go through the restart process up to the blue screen at the end, where the little spinning doohickey will appear and stay there indefinitely, forcing me to hard restart.

    It didn't seem to happen before I got my iPad but happens about every other day now. At first it seemed to happen after I had my iPad charge from my computer, but now it seems to happen regardless. One time it hung while syncing with my iPhone and required me to restore it since the phone got messed up.

    I've done everything I can think to do to get to the source of the problem and I can't figure it out. I've looked through logs and didn't see problems (granted, I don't know if I'm looking at correct logs or if I'm looking for the right events). I have repaired permissions, and that seemed to help but not fix the problem.

    I bridge my iPad to my computer through Internet connection sharing, since I have an Ethernet internet connection. I created Automator work flows to turn it on and off (and AirPort) as I never leave it on when not using it.

    Does anyone have any bright ideas?
  2. macplusbris macrumors newbie

    Jul 5, 2010
    Re: iMac i7 Random Hang

    I'm having exactly the same problem. It has happened 3 times so far and exactly how you described it. Not sure yet of the cause, will suss it out, if I find anything will let you know.
  3. Makosuke macrumors 603

    Aug 15, 2001
    The Cool Part of CA, USA
    Similar issue -- apparently related to SD card slot

    I was going to start a new thread, but this is somewhat similar to my issue, so I'll try piggybacking first.

    My issue is thus: Periodically (let's say once every 1-2 weeks) my i7 iMac will start with the "every program that attempts to poll connected volumes hangs in unrecoverable beachball" symptom.

    That is to say that everything runs properly, but if a program attempts to check all attached volumes (for example, open a save dialogue), it will hang. This is a "blocked I/O hang" (or whatever that's technically called when a process is waiting for a disk that isn't responding), meaning even kill -9 won't work on it. Reboot (or even "sudo shutdown now") just hangs at the spinning wheel. Killing the user's loginwindow process doesn't help, either--lower-level stuck processes still prevent proper restart.

    I've checked all the obvious--the internal hard drive is fine so far as I can tell, firmware and OS are fully updated, done all the standard resets and troubleshooting procedures. Now, I also have an older MBP running the same OS and software in a very similar use case, and it's absolutely rock solid, so it's not a universal OS bug, nor something to do with the way I use network volumes from a home share (which was my first guess--prior to 10.5 flakey network volumes frequently caused hangs like that).

    I'm now beginning to suspect the SD card reader, though. In particular, I recently had a "can't restart the system" hang directly tied to an SD card from my camera in the internal reader that refused to eject, and on closer inspection showed the unix processes associated with it as "stuck". Yanking the card to try and kick the stuck processes back in (which I've had work on other flaky devices to remove the blocking I/O) didn't do anything. Could well be that the other times an SD card was also inserted (quite possibly through sleep/wake cycles) sometime shortly before the hang.

    I'm not positive it's the SD card reader, but that's the only significant disk-related use that's different from my MBP that's stable, so it's currently my suspect.

    The fact that both my wife and I use it, and have simultaneous logins running, may also be a factor--10.6 seems to get confused as to who has permission to access what mounted network share on occasion, so that's the other thing I'm looking at.

    Has anybody else who uses the built-in SD card regularly had any hanging/beachballing issues?

    Any OTHER suggestions as to what I might try?
  4. jillync macrumors newbie

    Aug 7, 2010
    Same behavior - why is it starting now??

    I am having the same behavior folks here have described.* We have had our iMAC for over 2 years with no issue and then just started happening a few weeks ago.I see no one has posted a reply to help for any of your posts.Any chance there's finally a MAC virus that has hit our machines?

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