Previous 1 2 Next 19 Replies Latest reply: Mar 8, 2014 8:23 PM by vanclute
Virgule Level 1 (55 points)

Boot Camp often fails to boot at all, leaving the iMac dead at the bootloader screen. Have to force shutdown by holding down power button. Full hardware test declared the hardware 100% functional. Disk Utility and chkdsk sees nothing but fire. This is intermitent/random and it proved impossible to "force" it's occurance. It happen when it darn well please?


First occurance goes back to late July 2011, a few days after a major thunder storm that caused pulsing power blackouts (as in, very short bursts - like turning off the power then immediately flipping it back on - too quick to actually shut the computer down). Surely, this must be the source of the issue? Right? Alas it doesn't adds up. Power supply of this house is very stable and reliable. Power fluctuations are unhearded of. It's also connected to a surge protected outlet. The system itself, in Mac or Win, is flat out stable. It does not freeze out of the blue like what a damaged power supply would cause. It only ever freeze upon choosing a partition via the boot camp interface.


Further observation as compared to normal boot procedure: Upon selection of the Windows partition, the LED on the USB mouse turns off then back on again a short moment later. Windows loads up normally. When the crash occurs, the LED never turn back on. It's just dead right there and then.


What's going on and what can I do to fix this? It feels like some hardware initialisation fails for some reasons. It's ough to be around the USB systems itself but what do I know anyway?


P.S.: Please, don't mention the dreaded format and re-install. It's a 20 hours job. I'm not going there. ty


Message was edited by: Virgule - changed a "foul" word

iMac, Mac OS X (10.7.3), i7, 8GB
  • The hatter Level 9 (60,930 points)

    Why not upgrade the surge protector to a UPS? good units are very affordable.

    Put all your sensitive equipment like modem/router, computer, electronics running off UPS.


    CyberPower SINE 1000VA/600W $137 92/


    Well, sometimes if you don't have backups, and refuse to do what you may need to....


    There are troubleshoolting tips and faqs I'm sure on the 'net.

    Starting with Windows 7 DVD for one


    Even OS X won't survive with forced (hard) shutdowns.


    If it only happens in Windows, and you were running OS X when the outage occurred...


    USB devices and cables can be hard to ID but swapping cables and stuff helps.


    As for Disk Utility, it does not look at drive sectors or files for issues.

    If you really want to scan a hard drive, use the vendor's own Linux or Windows utiilty to recertify the sectors.


    If you haven't done any deep cleaning of files, registry, even uninstall and reinstall components.


    I just did a reinstall. Partially to be a test run for when I have to install Windows 8 next week, also to clear up a problem I had, possibly a rogue web site using a rootkit to hide files and icons and programs disappeared and icons became generic. So yes I don't take it lightly, but the new install runs much much better (over two years since last install).


    AHT is not a 100% reliable at finding everything, only what it actually is designed or suppose to look for.


    A semi-loose DIMM or faulty can be enough, and not likely AHT or Memtest will find it, but Windows does tend to spot a problem with RAM during installs.


    CCleaner 3.x

    Driver Sweeper 3.x

    START: run %TEMP% - Select All and send to Recycle


    Lion Recovery - show all hidden partitions and check health of all, hidden debug menu in Disk Utility can be enabled in command line


    Some partitions (GPT, EFI, System, Volume Information Block) are only tested during format where each sector does get a thorough check for errors because they can't be mapped out later. When you do chkdsk etc you only test user partition areas and not the 'entire' drive, unless doing a full initialization. And GPT requires that the VIB and also the backup VIB both be error free - in the past the backup VIB if it failed was "optional" though, it is not now.


    If you clone OS X then it is easy to move it to another drive and also to do full initialization and restore. If 3 days of your time isn't an option maybe time to invest in program(s) and methods that can backup and restore.


    Trying to find the needle in haystack that you have limped along with I guess since July (since installing Lion? maybe ?) can take 3 days probably, unless you are lucky enough to replace a mouse or cable on first step and it all goes away (hit the lottery or get hit by lightning odds)

  • capaho Level 4 (3,655 points)

    Do you have any USB drives attached?  I ran across a problem where Windows will not boot in Boot Camp if a Mac formatted USB drive is attached.  Adding a small FAT partition to the drive solved that problem for me.

  • LexSchellings Level 6 (8,732 points)

    What version of Windows is in the bootcamp partition?

  • Virgule Level 1 (55 points)

    Thanks you all. Any help I can get is a good thing.


    I enabled debug menu in Disk Utility. It reports disk0s1, Macintosh HD, Recovery HD and BOOTCAMP.


    I have spent my fair share on troubleshooting this and I am still dumbfounded, therefore this post. It really feels random. It's like this computer have the temper of a woman, so to speak.


    I have several USB doodads connected at all times. None of them are always powered on (except keyboard and mouse, ofc). All have their own power supply but many are connected via USB hub. The computer has frozen with and without external devices connected, powered on or off. If simply having something connected to the port at all is all it take to cause a crash, then there is a hardware problem in there.


    Boot Camp is running Windows 7 Professional, 64 bits (retail). The iMac came with Lion. It has never been re-installed.


    A small FAT partition, huh? I guess it's worth a try.

  • LexSchellings Level 6 (8,732 points)

    I suppose you have used Bootcamp 4.0.1 to make the Windows partition? A year ago there were some issues with the Bootcamp 64-bit Windows drivers.

  • Virgule Level 1 (55 points)

    Yes, it is 4.0.1. That is what came along the iMac.

  • LexSchellings Level 6 (8,732 points)

    How long would it take to make a second bootcamp partition with windows-7-64bit (if that is possible at all)?

  • The hatter Level 9 (60,930 points)

    Trouble(shoot) = eliminate variables and try one at a time and always be suspect of any device, drive, even if "only" connected but powered down. Disconnect until you find the needle in haystack.


    And don't create more partitions. unless you know it is unsupported, adds more risks and trouble and will fail and make matters worse, even on a good working system.

  • capaho Level 4 (3,655 points)

    Virgule wrote:


    A small FAT partition, huh? I guess it's worth a try.


    That's what solved the problem for me.  I suspected the problem, at least in my case, was related to USB because it kept cycling through the USB devices at boot time.  I disconnected all of them and then reconnected them one at a time until I found the USB drive that was the culprit.  Since it was Mac formatted I thought that might be the problem.  I added a small FAT partition and that solved it, Windows 7 boots up the first time every time now.  The problem ultimately has to be with the Boot Camp boot loader, but adding the FAT table was a workaround that worked.

  • capaho Level 4 (3,655 points)

    It looks like I need to retract my previous comments.  The boot failure problem has returned.  As far as I can tell, it still looks like a USB problem.  If a drive with a non-Windows partition or an auto power enabled drive is attached it will hang the boot, I suspect because the boot loader hangs before it can find a bootable partition.  I'm guessing it's either a Mac firmware problem or a problem with the Boot Camp boot loader that is in need of a bugfix update from Apple.

  • vanclute Level 1 (5 points)

    I just wanted to add my experience of problems with USB preventing Windows from booting in Boot Camp.


    In my case it was actually my USB hub that was the culprit. Once I narrowed it down to the hub it self, I found that removing the hub altogether would cause windows to boot perfectly fine and have no more issues.


    I'm going to be getting a new hub this weekend I think.   This was a very cheap one.

  • The hatter Level 9 (60,930 points)

    I've seen USB hubs cause other problems, first for this but the hub works after Windows is loaded?


    Have to remember this one.

  • Virgule Level 1 (55 points)

    Hi again. For the record, the boot problem have not reoccured since several months. There has been no replacement, addition and neither removal of hardware since OP. I am quite uncertain about what caused the problem in the first place just as well as what fixed it.


    My best account, as silly as it may sound, is that the problem appeared out of nowhere then went away seamingly on it's own. Somehow.


    I'll just go ahead and blame the gremlins. So, they say they are imaginary creatures?


    Have a good day.

  • vanclute Level 1 (5 points)

    Yep, that's the most interesting bit... if I plug the hub in AFTER Windows has booted, it works just fine.


    I've had hints that this hub is a POS for a long time... devices spontaneously dropping of and coming back immediately, and now my new UPS (that has a USB connection) telling me a couple times a week that it's lost power, when it hasn't.


    I've always bought the cheapest hubs I could find, thinking they're all the same... but after similar problems with 2 different ones, and now an absolute definitive diagnosis... I think I'm going to splurge for a good, name-brand hub.

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