DMG's failing

Discussion in 'Mac Basics and Help' started by chriscaines, Jan 25, 2011.

  1. chriscaines macrumors newbie

    May 16, 2008
    This is becoming so frustrating. Software Update fails, all Apple DMGs fail to mount (with various errors) and I cannot download anything from iTunes.

    I've followed forum after forum, trying various work arounds but still I'm having no success.

    I've restored my computer to factory settings twice, tried manual download of Software Updates but cannot mount as the file is corrupt, accessed private/etc/hosts and adding

    I've read somewhere that the problem could be with a new router - as this was replaced at the same time, but I can't install old router and we got rid :S

    I'm at the end of my tether... can someone help at all? I really don't know what to do.
  2. Hugh macrumors 6502a


    Feb 9, 2003
    Erie, PA
    When you said that you restored to factory settings twice. Do you mean that you did a format clean install? If not if you can try that, to see if that fixes your problem.

  3. Mactrillionaire macrumors regular

    Oct 16, 2010
    DMGs don't ordinarily get corrupted unless the hard disk they are stored on is failing or unless an error occurs in transmitting them from one location to another. Your best bet is to keep track of the MD5s and check from time to time to see if they have changed even when you haven't updated them. That's the only way you can know for sure at what point (either hard disk or network connection) that the failure has occurred.
  4. Nermal Moderator


    Staff Member

    Dec 7, 2002
    New Zealand
    I don't think the DMGs are corrupted, rather the system is reporting them as corrupted when they're not. I've seen this before (way back in OS 10.3.2!) and had to reinstall from scratch (there may be another way to fix it, but I just needed it working and didn't have time to dig around for a solution).
  5. old-wiz macrumors G3

    Mar 26, 2008
    West Suburban Boston Ma
    I had the same issue some time back. I had a .dmg that would only open in 10.5 (or some such) and I was running 10.<5-1>. Once I upgraded to 10.5 all the same .dmg was fine.
  6. chriscaines thread starter macrumors newbie

    May 16, 2008
    Well I thought I had fixed my problem, but again I'm having issues. I've rerouted the DNS settings through to OpenDNS which seemed to help for a little while, but I just can't download any of the Software updates, which is annoying the hell out of me. Try to manually download Safari from Apple site, for example, and the DMG can't mount. Force it to mount using some software and there is an error every time.

    Someone please save me - I'm about to throw my iMac out of the window!
  7. kuwisdelu macrumors 65816

    Jan 13, 2008
    My guess is it's your internet connection. It may be your DNS, router, or just your ISP.

    That kind of thing happened to me for a while, and it usually turned out to be that the .dmg's didn't completely finish downloading (even though they said they did), which will result in them appearing corrupted or unable to mount.

    To easily diagnose this, try going to a coffee shop or somewhere with a good, free WiFi connection and try downloading the .dmg again. See if it mounts this time. If it does, it's probably a problem with your connection (DNS, ISP, or router). If not, then it may be disk or system problems...

    ETA: Just noticed it's an iMac, making the above advice not terribly useful... if you use a wireless router, can you try connecting directly via ethernet and seeing if that helps (in case it's the router)? It did for me.

    (In my case, it happened to be a problem of the cat sitting on the router, causing it to overheat, causing it to drop my connection, causing .dmg's and such to say they were finished downloading when they weren't, causing my system to believe they were corrupted, when they were in fact just incomplete.)
  8. Mikelnz macrumors newbie

    Feb 16, 2011
    Same problem too

    I'm having the same problem though I can open the DMG's on my older mac... they must be complete and downloaded properly ....I have done a repair on my mac though everything seems just fine..

    Anyone switched on enough to work this one out?

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