flashing ? icon since yosemite install
Ever since i upgraded my MB Pro Late 2011 to Yosemite i am constantly getting a flashing ? icon it takes anything upto 5 attempts to boot properly
Sometimes it will boot 1st time but the sound doesn't work so I'm forced to reboot again and then its pot luck on how many times it takes to boot
I am at my wits end with it now
I have tried (all not solved it)
Selecting the hard drive in settings start up disk
Disk Utility and verifying the drive (No faults found)
Upgrading from Mountain Lion to yosemite
Installing Yosemite as a fresh install after formatting hard drive
Tried a different hard drive (same issue)
I have tried an alternative hard drive cable (same issue)
I have run Apple Hardware test and no faults found
MacBook Pro (13-inch Late 2011), OS X Mavericks (10.9.4)