Mac Pro freezes

[Max-mac-user]

I have a 2007 Mac Pro, running OS X.7.5. I recently got an iMac running Yosemite. I booted the Mac Pro in TARGET mode to be able to access its folders from the iMac. I have a Firewire connection between them, as well as being able to use File Sharing over my ethernet network.
Since doing this & restarting the Mac Pro, it has had nothing but problems!
Like not allowing me to type in the password to log in until I do a 'clean' restart, sometimes I have to restart it 2 or 3 times! Or now it starts up fine but the screen (not the curser) freezes after about 10 minutes of use?
I tried resetting the PRAM & fixing the permissions. What else can I do to get it back to where it was before I booted it in TARGET mode?

 

[honestone]

Do you have an external (and preferably bootable) backup of the stuff on your Mac Pro? That will help a lot.

Also, how old is the hard drive (or drives?) inside the Mac Pro?

When you had the Mac Pro in Target Disk Mode, were you able to access folders on it via the iMac? Did you do anything else while the Mac Pro was in Target Disk Mode?

If you have a backup, then it would be good if you actually repaired the disk inside your Mac Pro. But, you need to first let us know about a back up.

 

[Max-mac-user]

Thanks. I only accessed some files while in target mode. Couldn't see a way to restart the 'targeted' mac pro without manually turning it off and on again.
I just tried restarting from a backup (on another internal drive) and using Time Machine to restore the System from a version a few days before this problem started, but the computer froze after it started to restore.
Now i'm trying to restart from a Disk Warrior cd. I also tried to scan for the problem with Tech Tool Pro v7 but it froze again in the middle of the process.
Now I'm thinking of re-installing the OS but don't know how I can do that without an actual CD to mount from.
and its not even starting when i hold down the shift key - endlessly spinning.
Its getting worse & worse the more I try and do!

 

[Max-mac-user]

Now its not starting at all! Endless spinning "wheel". Time to take it into a Mac repair shop I think. If my usual startup disk crashed, wouldn't it start up with the duplicate system on the other internal drive?