2010 i7 27" iMac: randomly dropping firewire and USB hardware

Discussion in 'iMac' started by HobeSoundDarryl, Sep 18, 2010.

  1. HobeSoundDarryl macrumors 604


    Feb 8, 2004
    Hobe Sound, FL (20 miles north of Palm Beach)
    I posted this in Apple support but haven't seen a response, so I wonder if this problem is only my own. Here's the story...

    I just got the latest & greatest iMac 27" i7 2TB with SSD (and 12GB ram) a few days after they launched (had it a bit more than a month now). Wow! It's great. To it, I've attached some USB hardware as well as a WD 4TB firewire 800 drive: Western Digital My Book Studio Edition II.

    Things seem to work well most of the time, but I've noticed more than once that attached hardware gets dropped. In particular, I've got a Parliant USB device (part of the Phone Valet package which makes the Mac a great voice mail machine) that is sometimes there and sometimes missing. It's hooked directly to the back of the iMac (not a hub), and I've tried switching which USB port it's plugged into on the Mac. This device worked fine for years hooked to a PowerMac G4. But now, it is often in the USB (attached devices) list, but sometimes it's gone. When it's gone, my business voice mail system is also offline... NO GOOD. I have to unplug and then plug it back in, or sometimes reboot.

    Similarly, I've got a USB scanner that is often in the list of USB devices but sometimes gone. Unplug and replug and it's there again.

    The WD is hooked to the firewire 800 port. I use it mostly for iTunes video media. It will simply disappear from time to time, and I don't get any kind of (the usual) "warning" message about a disconnect without ejecting. It's just there and then it's gone. This is my second WD drive; I returned the first one for this same reason, assuming I had a bad drive. A second one doing the same thing makes me think it might be the iMac instead. I used Disk Utility on both WD drives. I even tried Disk Warrior on the first one that I returned. Neither found any fault with the WD format or hardware.

    Like the PhoneValet USB attachment, the WD will come back by unplugging the firewire, waiting a few seconds and then plugging it back in. Or I can reboot the Mac.

    But in both cases, what I want is for them to always be "on", not (seemingly) randomly there and then not there. I starting to suspect a bug in the hardware ports on the iMac since both a firewire (2 in a row actually) and at least 2 USB devices are exhibiting these disappearing sequences.

    I've got the iMac hooked to a good battery backup/surge suppressor, so I'm pretty confident the problem is not related to spikes/brownout/blackouts.

    Everything else works great and has since the day I received it. I work many hours each day on the Mac and all seems fine, except for these attached device drops.

    Anyone have any suggestions? Anyone got the same kinds of problems?

    Is this a "take it to the Apple store issue?" And, if so, I'm convinced that I can't demonstrate the problem to them as I can't seem to make hardware disappear on demand.

    Thanks for any input/suggestions!
  2. Evo-L macrumors member

    Feb 28, 2008
    Maybe in your system preferences you have the HDD's set to turn off when the computer sleeps?

    Just an idea, :cool:
  3. HobeSoundDarryl thread starter macrumors 604


    Feb 8, 2004
    Hobe Sound, FL (20 miles north of Palm Beach)
    That's a good idea. And yes, I have the box checked in Energy Saver to put the hard drive to sleep when possible. Why does this affect only the external hard drive though (meaning why can't the external come back like the internal hard drive)? And what's it got to do with USB devices that aren't storage related (a scanner and a type of phone modem-like device)?

    I noticed this thread: http://forums.macrumors.com/showthread.php?t=1016354 which is a guy who has pulled the optical and now has a 27" imac with 2 SSDs and a hard drive (3 internal drives). He's got them set up so that he can boot from one of the SSDs or from the hard drive. Whichever drive he boots from is the one that will still be there when the iMac wakes, but the others will be gone. That seems similar to my situation except that my internal drives (the boot drive SSD and the 2TB internal) are always there (they're not doing these random disappearances).

    I do have my iMac set up to go to sleep at night and auto wake in the morning (every day). Most of the time, everything is fine. These external hardware disappearances for me seem to be happening without an iMac sleep cycle in between, such as during the day when I'm using the computer and notice that calls aren't getting picked up by Phone Valet (occasionally), or trying to scan something and the software can't see the scanner, or trying to watch something on the external firewire drive and iTunes can't find the file (because the WD has disappeared).
  4. stix666 macrumors regular

    Nov 13, 2005
    I get this occasionally too. I have a Mac mini with one FW800 HDD, one USB HDD and a HDD connected via airport. The airport HDD never disappears, the others do occasionally.

    I suspect this is at least partly software issue
  5. Rfholland macrumors newbie

    Dec 12, 2011
    Any solution to iMac dropping USB devices?

    HobeSoundDaryll, have you found a solution to the problem? I am having the same issue with iMac dropping my DAC USB SOUND device. Thanks for any insights.
  6. johnjay1776 macrumors member

    Jul 25, 2008

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