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My hard drive failed so I replaced it and now when it starts I get a circle with a slash. I have tried to reset the pram holding the Command, option +r+p , I think that was the combination. I was able to hold the option button down at start up and the recovery icon came up. As soon as I clicked it I get the circle with the slash again. Please help!
Sounds to me like you are probably trying to install a system that is to high for your machine. Exactly what machine do you have? What system are you trying to install and where did you get it? Does it meet the system requirements for the operating system you are trying to install. The install may also be to old a download. Also did you first format the new drive GUID and MacOSX?
Did you install OSX on the replacement drive? Also you should correctly identify your macbook using the Ultimate Mac Lookup from Everymac: http://www.everymac.com/ultimate-mac-loo…
@rcl1964 , when replacing a hard drive, you normally need to reload the operating system and other programs that came with it. If you have a fast internet connection, you can use Internet recovery. Otherwise, if you know someone with a working Mac, you can have them make a bootable USB installer for OS X.
SOLVED: MacBook Will Not Start Up After macOS Update
I have a MacBook pro running MacOS Mojave. For the past year or so, every time a new MacOS update rolls out, and is attempted to be installed on my MacBook, it ends up displaying the circle slash (Prohibitory Symbol). Rebooting still produces a prohibitory symbol. I’m still able to boot into recovery mode (CTRL-R at Startup), however running disk repair on my MacBook HD does NOT solve the problem. I have also tried: (a) specifying the startup disk (problem still persists); (b) attempting to start in safe mode (problem persists); doing the NVRAM reset (problem persists). In the past, the only way i was able to get around the problem, is by re-formatting my HD, installing latest version of Mojave OS, and then migrating all my data from my TimeMachine backup.
This happened again the other day with the recent Mojave update 10.14.2. My computer automatically installed the update overnight, and in the morning, my screen was showing circle slash. This time i did some more research, and discovered that the issue may be caused by UNSIGNED KERNEL EXTENSION (KEXT) files existing on my HD.
Kernel Extension is a piece of code that extends the capability of the base kernel of an operating system. The kernel typically manages I/O requests, and in OS X, the file ends in “.kext.”
Starting with Yosemite, kernel extensions must be code signed by the developer with Apple authorization or OS X won’t load them. Sometimes these un-signed kernel extensions cause this headache after an OS X or macOS update.
USING TERMINAL COMMANDS IN RECOVERY MODE, YOU SHOULD BE ABLE TO RESOLVE THIS PROBLEM BY REMOVING UNSIGNED KEXT EXTENSIONS FROM LOCATION: /Volumes/<your system’s drive name>/Library/Extensions/
After I removed the following KEXT files from the /Volumes/<your system’s drive name>/Library/Extensions/ directory, my MacBook booted up properly, and finished installing the Mojave update.
UNSIGNED KEXT EXTENSIONS REMOVED FROM Directory: <your system’s drive name>/Library/Extensions/ (note: this is DIFFERENT directory from /System/Library/Extensions/)
BJUSBLoad.kext (Creator: Canon) CIJUSBLoad.kext (Creator: Canon) ParagonSnapshot.kext (Creator: Paragon) ufsd_NTFS.kext (Creator: Paragon) VDMounter.kext (Creator: Paragon) LittleSnitch.kext (Creator: LittleSnitch)
Note: When I removed these KEXT Extensions, the “circle slash” problem did not resolve until i finally removed: ParagonSnapshot.kext and VDMounter.kext
FURTHER DETAILS: Below is a link to a useful article which provides some helpful information regarding: MacBook Will Not Start Up After macOS Update, How-To Fix https://appletoolbox.com/2016/10/macbook… In that article, the section titled “Un-Assigned Kernel Misfiring” explains how to boot into recovery mode and launch Terminal utility. However, one problem with that article is that the kextstat command is not available in Terminal utility running in recovery mode.
As a work-around, these are the steps i took to solve the problem:
- Boot to Recovery (with CMD + R or CMD + Shift + R if you don’t have recovery partition)
- First, pick Disk Utility, select your main disk and Mount it; this is required if your disk is encrypted and requires password to be mounted
- Now select Disk Utility -> Quit; then Utilities -> Terminal
- Begin typing in Terminal following commands: 4a. cd /Volumes/ 4b. cd <your system’s drive name> (Note: If your system drive has any spaces in it’s name, then put the name in single quotes. For example, my MacBook boot drive is called “MacBook HD”, so the command I would type is: cd ‘MacBook HD’ 4c. cd library 4d. cd extensions 4e. ls (Note: first letter is a lower case L) After you type ‘ls’, you should see a list of KEXT extensions like this: ACS6x.kext CIJUSBLoad.kext ATTOCelerityFC8.kext CalDigitHDProDrv.kext ATTOExpressSASHBA2.kext HighPointIOP.kext ATTOExpressSASRAID2.kext HighPointRR.kext ArcMSR.kext PromiseSTEX.kext BJUSBLoad.kext SoftRAID.kext
The KEXT extensions listed above are all ones properly signed by Apple. These KEXT extensions can remain, but if you have other KEXT extensions listed, chances are that some or all of those others are causing the issue.
If you see any of these extensions (listed below), you should be able to safely delete them in order to fix your problem. I’d recommend removing each extension, one at a time, then rebooting to see if it worked, and if not, repeat steps above and delete next one. Based on my limited research, the ones i’d recommend deleting first are: ParagonSnapshot.kext (Creator: Paragon) VDMounter.kext (Creator: Paragon) LittleSnitch.kext (Creator: LittleSnitch) ufsd_NTFS.kext (Creator: Paragon)
While in Terminal utility (in Recovery mode), to delete (or remove) a desired KEXT extension (eg., LittleSnitch.kext) type:
rm -r
- quit the terminal and restart
Hope this helps! :) Good luck!!
If you don’t have a working OS on the system you can’t get access to the setting. So the only way I can think of here is to reset the NVRAM How to reset NVRAM on your Mac or using Target Disk Mode Use target disk mode to share files between two Mac computers using a second Mac to install the OS from. Here you still need to backwind the date as well. Go into the the Date & Time control panel and disable Set date & time automatically and then alter the date back to a the point the El Capitan was available (2016) then restart and then the installer should work. Just remember to select your system as the target drive. The last possibility is to create an OS installer USB to boot up with to alter the date How to make a bootable OS X 10.11 El Capitan installer drive and run the installer from it.
