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"Do Not Enter" symbol appearing on startup grey screen

Hello,

I went to start up my 2010 MBP with 4gb of ram and a 240 gb SSD (installed in January) and i get a symbol like a "do not enter" symbol. i can not get around this. i tried a PRAM reset. i cant imagine it being the SSD as it is basically brand new and hardly any use. do i need to a reinstall of my OSX? i have it on a 8GB usb key.


any help would be great

MacBook Pro, OS X El Capitan (10.11.2)

Posted on Mar 3, 2016 11:40 AM

Reply
21 replies

Mar 3, 2016 11:47 AM in response to Brohemeth

Mac OS X- Gray screen or prohibitory sign appears during startup

Mac OS X- Gray screen appears during startup

Tackle your Mac booting to a gray screen | MacIssues

Question (?) Mark, Blinking Folder, or Gray Screen at Startup


These are related but not identical issues. Their causes are outlined in Intel-based Mac- Startup sequence and error codes, symbols. Solutions may be found in:


A flashing question mark or globe appears when you start your Mac

Mac OS X- Gray screen appears during startup


In most cases the problems may be caused by one or more of these:


a. Problem with the computer's PRAM - See Resetting your Mac's PRAM and NVRAM.

b. Boot drive's directory has been corrupted - Repair with Disk Utility.

c. Critical system files are damaged or deleted - Reinstall OS X.

d. The disk drive is physically non-functional - Replace the hard drive.


Note that the information I have provided is what Apple recommends, If other users suggest different solutions than found here, then be sure what they recommend does not impact on your warranty, if any, or ability to get continuing Apple service.


Please don't start removing drives or changing cables unless you know what you are doing and have exhausted other non-invasive alternatives outlined here. If you perform any work yourself that is unapproved by Apple, then you will void any warranty you may have and lose all further Apple Support.



Repair the Hard Drive and Permissions


Boot from your Snow Leopard Installer disc. After the installer loads select your language and click on the Continue button. When the menu bar appears select Disk Utility from the Utilities menu. After DU loads select your hard drive entry (mfgr.'s ID and drive size) from the the left side list. In the DU status area you will see an entry for the S.M.A.R.T. status of the hard drive. If it does not say "Verified" then the hard drive is failing or failed. (SMART status is not reported on external Firewire or USB drives.) If the drive is "Verified" then select your OS X volume from the list on the left (sub-entry below the drive entry,) click on the First Aid tab, then click on the Repair Disk button. If DU reports any errors that have been fixed, then re-run Repair Disk until no errors are reported. If no errors are reported click on the Repair Permissions button. Wait until the operation completes, then quit DU and return to the installer.


If DU reports errors it cannot fix, then you will need Disk Warrior and/or Tech Tool Pro to repair the drive. If you don't have either of them or if neither of them can fix the drive, then you will need to reformat the drive and reinstall OS X.


The main difference if you are using Lion or Mountain Lion is that you must first boot from the Recovery HD. Simply boot from the Recovery HD to perform the above.


Reinstall Snow Leopard Without Erasing The drive


1. Repair the Hard Drive and Permissions


Boot from your Snow Leopard Installer disc. After the installer loads select your language and click on the Continue button. When the menu bar appears select Disk Utility from the Utilities menu. After DU loads select your hard drive entry (mfgr.'s ID and drive size) from the the left side list. In the DU status area you will see an entry for the S.M.A.R.T. status of the hard drive. If it does not say "Verified" then the hard drive is failing or failed. (SMART status is not reported on external Firewire or USB drives.) If the drive is "Verified" then select your OS X volume from the list on the left (sub-entry below the drive entry,) click on the First Aid tab, then click on the Repair Disk button. If DU reports any errors that have been fixed, then re-run Repair Disk until no errors are reported. If no errors are reported click on the Repair Permissions button. Wait until the operation completes, then quit DU and return to the installer.


If DU reports errors it cannot fix, then you will need Disk Warrior and/or Tech Tool Pro to repair the drive. If you don't have either of them or if neither of them can fix the drive, then you will need to reformat the drive and reinstall OS X.


2. Reinstall Snow Leopard


If the drive is OK then quit DU and return to the installer. Proceed with reinstalling OS X. Note that the Snow Leopard installer will not erase your drive or disturb your files. After installing a fresh copy of OS X the installer will move your Home folder, third-party applications, support items, and network preferences into the newly installed system.


Download and install Mac OS X 10.6.8 Update Combo v1.1.


Reinstalling Lion/Mountain Lion Without Erasing The Drive


Boot to the Recovery HD: Restart the computer and after the chime press and hold down the COMMAND and R keys until the menu screen appears. Alternatively, restart the computer and after the chime press and hold down the OPTION key until the boot manager screen appears. Select the Recovery HD and click on the downward pointing arrow button.


Repair the Hard Drive and Permissions: Upon startup select Disk Utility from the main menu. Repair the Hard Drive and Permissions as follows.


When the recovery menu appears select Disk Utility. After DU loads select your hard drive entry (mfgr.'s ID and drive size) from the the left side list. In the DU status area you will see an entry for the S.M.A.R.T. status of the hard drive. If it does not say "Verified" then the hard drive is failing or failed. (SMART status is not reported on external Firewire or USB drives.) If the drive is "Verified" then select your OS X volume from the list on the left (sub-entry below the drive entry,) click on the First Aid tab, then click on the Repair Disk button. If DU reports any errors that have been fixed, then re-run Repair Disk until no errors are reported. If no errors are reported click on the Repair Permissions button. Wait until the operation completes, then quit DU and return to the main menu.


Reinstall Lion/Mountain Lion: Select Reinstall Lion/Mountain Lion and click on the Continue button.


Note: You will need an active Internet connection. I suggest using Ethernet if possible because it is three times faster than wireless.

Mar 3, 2016 2:37 PM in response to Brohemeth

Usually means you either did it wrong or don't have a Recovery HD on the drive.


Clean Install of Snow Leopard


1. Boot the computer using the Snow Leopard Installer Disc or the Disc 1 that came

with your computer. Insert the disc into the optical drive and restart the computer.

After the chime press and hold down the "C" key. Release the key when you see

a small spinning gear appear below the dark gray Apple logo.


2. After the installer loads select your language and click on the Continue

button. When the menu bar appears select Disk Utility from the Utilities menu.

After DU loads select the hard drive entry from the left side list (mfgr.'s ID and drive

size.) Click on the Partition tab in the DU main window. Set the number of

partitions to one (1) from the Partitions drop down menu, click on Options button

and select GUID, click on OK, then set the format type to MacOS Extended

(Journaled, if supported), then click on the Apply button.


3. When the formatting has completed quit DU and return to the installer. Proceed

with the OS X installation and follow the directions included with the installer.


4. When the installation has completed your computer will Restart into the Setup

Assistant. After you finish Setup Assistant will complete the installation after which

you will be running a fresh install of OS X. You can now begin the update process

by opening Software Update and installing all recommended updates to bring your

installation current.


Download and install Mac OS X 10.6.8 Update Combo v1.1.

Mar 3, 2016 3:40 PM in response to Brohemeth

My friend just bought a used macbook pro and the min she turned it on it was a grey screen with a folder and circle with a slash though it.

I would like to help her but I know nothing about macbooks. I tried the Command and R button together, nothig happens.. does anyone know what I can do to get this working g for her?

"Do Not Enter" symbol appearing on startup grey screen

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