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prohibitory sign

  1. K

    Prohibitory sign on RESTART after installing Samsung 870 EVO Sata 2.5" SSD on Mini Late-2012

    I'm trying to upgrade my late-2012 mini stock HDD with Samsung 870 EVO SATA 2.5" SSD. At first I was having issue with getting disk utility to detect the drive, i thought it was a loose connector so i redid my setup and it popped up. Then during the OS installation using bootable Catalina USB...
    • kolz
    • Thread
    • mac mini late 2012 prohibitory sign restart samsung ssd
    • Replies: 18
    • Forum: Mac mini
  2. W

    Need Help Reinstalling MacOS

    Hey guys I'm new to this Forum and I was wondering if you guys could help me out with some issues I'm having with 3 Macbook pros that i recently got from my friend that runs a computer recycling business. The Macbooks have an operating system on them that works fine but it is password locked...
    • weichjty
    • Thread
    • booting to usb macbook pro prohibitory sign recovering recovery
    • Replies: 9
    • Forum: MacBook Pro
  3. S

    Prohibitory symbol on boot with new Samsung 860 Evo SSD in 21.5" iMac Mid 2011

    Hello all, I recently bought a 500 GB Samsung 860 EVO 2.5” form factor SSD to swap it out with the primary HDD in a mid 2011 21.5” iMac. Problem is, the computer doesn’t boot (shows a prohibitory sign) whenever the 860 is inside the chassis and connected to the motherboard through SATA, however...
    • syntholog
    • Thread
    • cable external boot drive imac prohibited prohibition symbol prohibitory sign prohibitory symbol ssd upgrade
    • Replies: 2
    • Forum: iMac
  4. bapurba007

    MacBook Air prohibitory sign on screen

    Lately I wanted to format my MacBook Air 2016 edition and for that I thought I should eject and erase Macintosh HD too and well somehow I did it and now I cannot install OS High Sierra on my MacBook Air because I have no storage slot for it. The “Macintosh HD” is gone and I’m left with OSX Base...
    • bapurba007
    • Thread
    • macbook macintosh hd os high sierra prohibitory sign
    • Replies: 10
    • Forum: MacBook Air
  5. M

    Error while clean installing macOS High Sierra

    Hi, I'm having a problem doing a clean install of macOS High Sierra on a MacBook Pro 13 early 2011 I installed a brand new SSD and tried to install High Sierra but I'm having issues I've tried doing Internet recovery and USB bootable but both won't work, the SSD works perfectly cause I tried on...
  6. Mfrazee

    Prohibitory Sign help!

    Hi everyone, new to the forum here. I don’t consider myself a computer wiz, though I know more than the average consumer. I’ve been having bizarre issues come up since installing High Sierra, so I tried to do a factory reset of my 2017 MacBook Pro. I erased my drive and restarted the...
    • Mfrazee
    • Thread
    • high sierra macbook pro (15" 2017) prohibitory sign startup disk startup error
    • Replies: 0
    • Forum: MacBook Pro
  7. O

    iMac (late 2009) with Samsung 840 SSD & High Sierra

    Hi guys, I've been running a late 2009 27" iMac with a Samsung 840 SSD (replacing the SuperDrive) on Sierra. I've had persistent problems for a while booting up to the 'prohibitory' symbol. Usually a second or third restart eventually boots successfully. Running Disk Utility reports no errors...
  8. G

    PLEASE HELP! Post-logic board replacement, having issues.

    Hey MacBook gurus.. Ready for a puzzle? So, here's the story. My buddy spilled coffee on his computer, it "turned off immediately," but I had him do a hard shut down anyways to be safe. We drained everything out, and dried everything off. Apparently he tried to turn it on again (against my...
    • GraphikGeek
    • Thread
    • logic board replacement macbook 13 prohibitory sign
    • Replies: 7
    • Forum: MacBook Pro
  9. RedFlag

    Prohibitory sign after Sierra update, unmountable partition

    Hello. Yesterday I decided to update to Sierra from El Capitan on both the disks on my Macbook Pro (mid 2012); the update on my SSD went without a hitch so I decided I'd update my other disk, too. I downloaded the .app and the installation started as normal; once it got to the point where I'd...
    • RedFlag
    • Thread
    • boot error boot fail partition partitioning prohibitory sign sierra update problems
    • Replies: 14
    • Forum: macOS Sierra (10.12)
  10. Synchrotron

    Prohibitory Sign when Installing Windows via Bootcamp

    Hello. As a disclaimer, I know very little about this subject matter so if you have a suggested solution please explain it to me like I'm 5. About two days ago, I began setting up Boot Camp on my Late 2014 iMac Retina 5K (27") running macOS Sierra 10.12.2, with the intent to eventually transfer...
  11. B

    Help please! Prohibitory Sign installing Leopard os x after using dban on 2008 imac

    Hi everyone, So I got an imac from work after we upgraded all of the computers. Its a mid 2008 imac, it was running os x Leopard 10.5.8 prior. Apparently they used DBAN on it to wipe out private/sensitive information. I tried burning a .dmg file for leopard 10.5 installation on my pc laptop...
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