Currently Being ModeratedNov 29, 2012 10:15 AM (in response to Francesco Marotta)
Welcome to the Apple Support Communities
Press Shift key while your computer is starting and see if you can use the Mac. If not, the graphic card is broken and you have to take the Mac to an Apple Store
Currently Being ModeratedNov 29, 2012 10:41 AM (in response to Francesco Marotta)
The usual exact symptoms from graphics card failure are that the "gear" spins for about the usual amount of time, and then stops or disappears and the screen stays static or changes to something unusable like a plain blue screen. This correlates with the instant that your graphics card is supposed to switch to "Automatic" and use the loaded driver. The symptoms are caused by its failure to work on automatic.
Your description is a little different from a simple graphics card failure.
I think you may benefit from Booting to Recovery_HD (if 10.7 or later) or booting to the Installer/Utilities DVD, but do not Install. Instead, answer only the "what Language" question and wait a quarter minute until the Menu Bar is drawn. Then choose Disk Utility off the Utilities menu.
Select your Boot Drive and check its SMART Status (lower right of the screen). Then Select your Macintosh_HD and ( Repair Disk ). Repeat until it comes clean or gets stuck, then copy the EXACT wording of any remaining problems here for additional advice.Mac Pro (Early 2009), Mac OS X (10.6.8), & Server, PPC, & AppleTalk Printers
Currently Being ModeratedNov 29, 2012 11:05 AM (in response to Grant Bennet-Alder)
I have 10.6.8.
I cannot boot with the utilities DVD, because it reamins stuck als odoing this.
I am trying now with Transfer mode via firewire, i can see the drives inside, the SMART Status is "not supported".
Currently Being ModeratedNov 29, 2012 11:11 AM (in response to Francesco Marotta)
SMART Status in only supported on Drives in Bays directly connected. This report you are seeing is not an error, since you are using FireWire Target disk mode rather that direct connection.
You should still be able to ( Repair Disk ), and that may be telling.
" A Mac that cannot boot from an appropriate Installer/Utilites DVD has a Hardware problem."
NB: this means a Full Retail DVD that it should boot from, not a Model-specific DVD shipped with a different model Mac.Mac Pro (Early 2009), Mac OS X (10.6.8), & Server, PPC, & AppleTalk Printers