I have a very weird problem with my 2009 Mac Pro; quad-core, 16gb RAM, HD7950 (flashed).
I've used a Crucial 480gb SSD with Sierra in an external TB case with my iMac 2012. I wanted to use this SSD in my Mac Pro. I got the SSD out of the enclosure. Put it in the Mac Pro drive bay, but I got a prohibited sign.
I taught the problem was I was using Sierra and the Mac could only run El Cap. So I used an El Cap usb installer/drive, but when I want to install the OS I don't see any drives to install it on. Also in Disk Utility no sign of an SSD at all...
So then I put in my good old Snow Leopard DVD and yes then I could see the SSD and install OS X 10.6.8! Now I taught to upgrade to El Cap, by downloading the El Cap installer from the Apple Support site. But when the machine reboots, to go to the installer, I get the prohibited sign again...
Maybe a bad SSD, but it works fine in 10.6 and in external enclosures. So it has to be the Mac Pro. I put in an old 640gb HDD and this drive doesn't get detected as well. In System Information I can see the drive in the correct drive bay, but it says 'unknown'.
So weird it works with Snow Leopard but not at all with El Capitan. Any ideas? Thanks!!
I've used a Crucial 480gb SSD with Sierra in an external TB case with my iMac 2012. I wanted to use this SSD in my Mac Pro. I got the SSD out of the enclosure. Put it in the Mac Pro drive bay, but I got a prohibited sign.
I taught the problem was I was using Sierra and the Mac could only run El Cap. So I used an El Cap usb installer/drive, but when I want to install the OS I don't see any drives to install it on. Also in Disk Utility no sign of an SSD at all...
So then I put in my good old Snow Leopard DVD and yes then I could see the SSD and install OS X 10.6.8! Now I taught to upgrade to El Cap, by downloading the El Cap installer from the Apple Support site. But when the machine reboots, to go to the installer, I get the prohibited sign again...
Maybe a bad SSD, but it works fine in 10.6 and in external enclosures. So it has to be the Mac Pro. I put in an old 640gb HDD and this drive doesn't get detected as well. In System Information I can see the drive in the correct drive bay, but it says 'unknown'.
So weird it works with Snow Leopard but not at all with El Capitan. Any ideas? Thanks!!