Ive created a bootable usb with mountain lion on it and when i hold down option and select the boot drive i get the prohibited symbol. any ideas ?
thanks again
thanks again
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Mac will not boot
- Thread starter drumminator
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the model year is a 2008 mac pro 8 core 3.0 ghz 16 gig ram 2 hard drives,i also have a macbook 2008 running mountain lion.Ive been using the desktop in target disk mode to install osx using the laptop but even then when i go to turn it on i get the prohibited symbol ? would disk repair help ??
thanks !
thanks !
used the laptop for the download an make the bootable usb but when i select the usb for the boot i get the prohibited symbol.
Ok, taking a punt, i would guess at driver incompatibilities between the laptop and desktop.
Look up your serial number on Apple's support site and see what model you have. If you have the Mac Pro (8-Core), Mountain Lion isn't supported on your Mac. If you have the Mac Pro (Early 2008), then you might've messed up somewhere in making your bootable USB drive as all versions of Mountain Lion are supported on that Mac.
Sorry to ask this ... but you did format the thumb drive for GUID JHFS+ before you transferred the bootable OS to it? 
The 2008 Mac Pro runs ML 10.8.2 just fine, and I have had no problems booting from thumb flash drives with mine.
Something is wrong with your USB drive configuration.
Good luck...
The 2008 Mac Pro runs ML 10.8.2 just fine, and I have had no problems booting from thumb flash drives with mine.
Something is wrong with your USB drive configuration.
Good luck...
Have you tried the bootable usb with other computers? Try it with your laptop. If you get the same problem, then you know the problem is with the bootable usb. Follow the instructions here to remake one.
i did not format the thumb drive i think that will be the next thing i try. if i cant get anything else to work im going to just bring it in to the IT guy at my school, hes all sorts of apple certified. Something else interesting to note.I ran the Mountain lion install from my macbook connected to my mac pro tower and selected the hard drive on the mac pro,ran through the install and everything and after i shut down the laptop and everything and go to boot back up i still get the prohibited sign.
thanks again for the help guys
much appreciated
thanks again for the help guys
much appreciated
What does it read if you boot in Verbose mode ( Cmd+V at startup bong). The last few lines should shed light on the problem.
The probable problem here is that it downloads a OS X version compatible with the Macbook and not the Mac Pro, there are driver issues and that's why you get the sign at startup.
Do as the above poster (monkeybagel) says and boot up with Command-v and tell us what you see, on top of the screen you might see "Incompatible CPU"
it said something about " this version of osx is not supported" ?? no sure what thats all about.and it said reason Mac-f4208da9
thanks !
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reason Mac-f4208da9
thanks !
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reason Mac-f4208da9
MacPro 2,1 or macPro 3,1????
If it is the 2,1 the Maximum OS version is 10.7.4, the 3,1 is able to run the latest OS.
Go to the Apple Menu, select About this Mac, then click more Info, System Profiler Opens and look up the Model Identifier.
its a mac pro 3.1 i cant even turn the computer on. wont boot into osx all i get is the prohibited symbol
all i get is the prohibited symbol
its a mac pro 3.1 i cant even turn the computer on. wont boot into osx
Then I think what is going on is what I said in one of my former posts, the macbook is downloading a OS version compatible with the Macbook and not the MacPro, your MacPro can run 10.8.2 but it seems to be incompatible with the OS X version you installed.
its a mac pro 3.1 i cant even turn the computer on. wont boot into osx
Can't you even boot to a DVD disk with the OS it came with?
hmm do you know how i would go about getting the one for a mac pro ??
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didnt come with one.i bought the computer used so the disks were MIA
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didnt come with one.i bought the computer used so the disks were MIA
Do you have a USB flash drive and computer (MacBook) that you can run the Lion Recovery Disk Assistant on and try booting the Mac Pro using that. That would pull down a fresh copy from Apple's servers if your machine will run it.
just tried the recovery assistant and when i go to open the usb i get the same thing, that damn prohibited symbol i feel like ive tried everything, ill probably just end up bringing it in to get looked at.
thanks for the suggestions !
more are welcome !
i feel like ive tried everything, ill probably just end up bringing it in to get looked at.thanks for the suggestions !
more are welcome !
just tried the recovery assistant and when i go to open the usb i get the same thing, that damn prohibited symbol
thanks for the suggestions !
more are welcome !
Bringing it in is the same as doing it yourself, as I said before you try to 'copy'/Install it from the Macbook which downloads an incompatible system, the only way you'll get Mountain Lion on it is the legal way, I think you have to buy Snow Leopard first and from there you can upgrade to Mountain Lion, Snow Leopard is needed as far as I know.
You are trying to install it the illegal way.
Edit: Look here for more information, you have to buy SL before you can Upgrade, it's in the Q&A. $ 19.99
To Quote one posters question:
And another:
Last edited:
yea i dont have a copy snow leopard on disk, thats one of the reasons for bringing it in (the IT guy can use his copy) plus if there is a deeper underlying issue it can be addressed by someone much more computer competent then myself.
thanks !
thanks !
I updated my above Post.
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He won't do that, you have to buy a copy of SL and then Upgrade to ML, you're going to spend more money on it by bringing it in.