Help! Desktop won't boot. Shuts off at apple logo!

[Mypoormac]

Hey everyone I've been searching for a solution for days and can't find anything
I have an iMac that will not boot. It turns on and gets to the apple logo, tries to load for a few minutes and just shuts off.
Now if there's no easy fix, I at least want to salvage some files.
At the moment I have the broken Mac connected to my MacBook via FireWire target disk mode. I can't mount the dead Mac, and it won't show up on my desktop via disk utility.
Now I'm currently on day 3 and counting using DiskWarrior, and after this long, I feel pessimistic.
Any thoughts?? Thanks in advance

 

[Kaveman]

If its shutting down then its probably a hardware fault! You could be damaging the very files you are trying to rescue, restarting it like that...

Best to get it to an AppleService Centre near you ASAP. If the Mac is not worth servicing, they should be able to put the HD in an external enclosure so you can access the files.