Prohibitory sign on start up

Discussion in 'iMac' started by eltoro75, Aug 25, 2015.

  1. eltoro75 macrumors newbie

    eltoro75

    Joined:
    Aug 25, 2015
    Location:
    Alexandria, VA
    #1
    System: 24 inch iMac (mid-2007) MA878LL

    Current configuration: This system has been working beautifully for the last 6 months since I upgraded the HDD with a 1TB SSD and installed 6GB RAM. I have enabled TRIM on the SSD and the system has been working better than it did when I bought it.

    What has changed: When installing the latest OS X Yosemite v10.10.5 and Security Update 2015-006, upon reboot the system started to load then after 20 seconds of progress it displays the prohibitory symbol. When starting in verbose mode system hangs at “Still waiting for root device”. Also, the system no longer has a chime on startup.

    Steps taken so far to restore system: I attempted the following startup options with a directly connected keyboard and the results follow each option:

    Start up in Safe Mode – Went straight to prohibitory symbol.

    Start up to Startup Manager – Went straight to prohibitory symbol.

    Start up from a bootable CD or USB thumb drive– Went straight to prohibitory symbol from CD and USB drive.

    Start up to Apple Diagnostics – Went straight to prohibitory symbol.

    Start up from OS X Recovery – Went straight to prohibitory symbol.

    Start up from OS X Recovery from USB drive in option mode– When booting with option key it shows my primary SSD and USB Drive. Tried booting from both only to end in the prohibitory symbol.

    Reset NVRAM – Went straight to prohibitory symbol, although this time the startup chime came back and has been working for every reboot since the reset.

    Reset the SMC - No effect, went straight to prohibitory symbol.

    Start up in single-user mode – Went straight to prohibitory symbol and displays “Still waiting for root device”.

    Start up in target disk mode using firewire – This works and I was able to access the SSD from my MacBook. I created an image backup of my SSD to another drive. I also ran diagnostics on the drive with disk utility which revealed the drive is in perfect condition.

    Start up in verbose mode – Went straight to prohibitory symbol after hanging at OSX Kernel debugger, displays “Still waiting for root device” and repeats every 60 seconds.

    Firmware restoration – Suspecting a firmware issue, I created a firmware restoration disk from my MacBook and followed the steps from the Apple support page to install. According to Apple, I was directed to hold the power button until I hear 3 beeps continuously, then insert the firmware restoration CD. When I hold down the power button I only get one long beep and then it tries to start up, only ending in the prohibitory symbol and doesn’t even try to read the firmware restoration CD.

    The very last operation I made was replace the logic board battery and repeating the NVRAM reset along with the rest of the previously mentioned startup options which resulted in the same results identified.

    I understand this system is 8 years old but it has been working so well I feel I need to at least try to keep it alive longer. The only thing I have not tried is reinstalling the OS from scratch, but if I can’t even boot into recovery mode or from CD/USB, I find it will be impossible to even get to that step. I suspect it is a hardware issue that may be preventing any further progress but I wanted to at least put it out to the larger community for help on this issue.
     
  2. macthefork macrumors 6502

    Joined:
    Feb 2, 2013
    #2
    How did you enable TRIM on earlier version of Yosemite? Or, what OS did you update from. Did you use the TrimForce command in Yosemite? Or TRIM Enabler, which turned off Kext signing, and modified the kernel extension? If the latter, use the instructions from this site to "undo" the modified kernel and turn Kext signing back on..

    https://www.cindori.org/trim-enabler-and-yosemite/
     
  3. eltoro75 thread starter macrumors newbie

    eltoro75

    Joined:
    Aug 25, 2015
    Location:
    Alexandria, VA
    #3
    macthefork,
    I used TRIM enabler but that was 6 months ago when I installed the SSD. The system has been working flawlessly since then. Do you think the Yosemite update caused some kind of disconnect with the TRIM? I wouldn't think that was the case but I know it can't be completely ruled out.

    Today, I managed to get the recovery menu to come up using my old HDD when booting up in option mode. I hooked up the old hard drive through the USB interface and it recognized the restore drive on the HDD. I had to wipe the SSD clean and I am attempting a restore from a backup I made in May. There are 3 hours left on the restore so I will update when it is complete.
     
  4. eltoro75 thread starter macrumors newbie

    eltoro75

    Joined:
    Aug 25, 2015
    Location:
    Alexandria, VA
    #4
    macthefork,
    Ok, I looked in to the kext signing and have a greater suspicion that this may be my issue. The update likely caused the drive to not be recognized by the driver and thus gave me the "still waiting for root device" error. I'll find out in less than 3 hours when restore completes. Thanks for the heads up, it's hard keeping up with all of Apple's shenanigans.
     
  5. randalf72 macrumors member

    Joined:
    Apr 25, 2014
    #5
    I had this issue with a 2012 MBP with a 256gb Samsung 840 SSD installed.

    I put the original HDD back in (thankfully I still had it), updated to Yosemite and all has been well since. I've no reason to suspect that cloning the HDD again and putting the SSD would be fine but it was definitely the OS upgrade that stopped the SSD from being recognised.

    It would be interesting to know if there are some brands of SSDs that didn't cause issues.
     
  6. eltoro75 thread starter macrumors newbie

    eltoro75

    Joined:
    Aug 25, 2015
    Location:
    Alexandria, VA
    #6
    Since all I had was my original install disks with OS X Lion, after a clean install I have been transported back in time to an OS from 2007. So, the issue was related to the SSD TRIM settings that were not compatible with OS X 10.10.4 security with kext signing. Tonight I will try to download the full 10.10.4 release, create a bootable USB drive and try to load that on the system.
     
  7. macthefork macrumors 6502

    Joined:
    Feb 2, 2013
    #7
    Do you have a backup of your system from prior to the 10.10.5 update (10.10.4)? If so, Backup from that, then turn off TRIM using the method you used to turn it on. The link in my first post also shows how to disable TRIM if you used TRIM Enabler. Then perform the update to 10.5.5. You should be able to re-enable TRIM by using the TRIMForce commands which are found by searching for them for Yosemite.
     
  8. rkaufmann87 macrumors 68000

    rkaufmann87

    Joined:
    Dec 17, 2009
    Location:
    Folsom, CA
    #8
    Update to 10.10.5 which is the most up-to-date version of OS X. Once you have installed 10.10.5 on the HD next clone 10.10.5 install to the SSD and then boot from the SSD and turn on TRIM by using the following command:

    Open Terminal and enter:

    Sudo trimforce enable

    You will receive a disclaimer, answer Yes to the next 2 questions and TRIM should be enabled on the SSD. Then re-install the SSD inside the iMac and you should be fine.

    Good luck
     

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