I'm in a pickle. Cannot boot from boot drive.

I had installed Yosemite onto brand new iMac and all was working fine.

Now I needed to prepare my old Mac Pro for sale by installing Mavericks onto another drive.

I couldn't download Mavericks on my iMac because of Yosemite so I booted the iMac from my old Mac Pro 10.9 drive. That works fine.

I downloaded Mavericks and then proceeded to install it on a 2nd external drive.

I wanted the new owner of the computer to see the same thing on screen when they first boot as you do with a brand new Mac, rather than have it boot into a fully installed OS with my choice of name.

When The installation got to the point of asking me what country I am in, I thought I would experiment by halting the install there. I turned off the iMac.

I then booted up from the new install and it came up with the same question about what country I am in so I thought that would be ok and any new user would continue to enter their details when they start up for the first time.

I now shut my iMac down and removed all external drives.

When I boot up now it is going into some sort of recovery mode. I get a screen telling me to switch on my mouse or track pad. Then I get Disk Utility.

Using "Startup Disk" from the Apple menu I select my Fusion drive with Yosemite installed and then restart. Again it boots into recovery mode.

What have I done to stop it booting?

I am typing this from my iMac booted from my old MacPro Mavericks drive.

I can see the Fusion drive in finder.

I would just copy some data off onto another external drive and reinstall the OS but most of the folders are inaccessible with a No Entry icon on the folder/

Is there simple way to make this drive bootable again (without loosing data) (I did verify and repair from Disk Utility but that never helped).

If I cannot do this without reinstalling then how do I access my data from the folders with the No Entry icons on so that I can back it up?

There are loads of photos I coped to the Fusion drive so that I could clear a drive off for the install of Mavericks so this is the only copy I have at the moment. :-/

 

For anyone else in a similar situation...

I reset the PRAM but it still booted up into a recovery mode but at least the Apple logo was white on a black screen like I was used to on Yosemite.

I then chose the correct boot drive from Startup Drive and did a restart.

It then booted up correctly.

I have now bought a 4TB drive for Time Machine which is now happily filling up.