Yesterday my screen (30" Apple Cinema) started showing symptoms of graphics card failure, jagged lines across the screen. I rebooted my Mac Pro and it was gone. Then it happened again an hour later, this time the machine didn't boot, I get the Apple logo, and then it hangs up and the screen is shifted to left (I get apple logo on left side of the monitor instead of the middle) and jagged lines all over. So the first thing I tested was using Target Disk Mode, it works. I can access my Mac Pro's internal HD's by TDM from my MacBook Pro. Then I tested single user mode, it does boot, I can't read what's written since the screen is shifted to left, but if I type (without seeing) reboot and hit enter, it reboots. So I assume the single user mode is working. What else can I try to 100% make sure it's my graphics card that failed and everything else is ok with Mac Pro? I already ordered a graphics card replacement but I wouldn't like to be surprised if the Mac Pro still doesn't boot when the card arrives. P.S. It won't boot from Apple Startup DVD either. Same thing happens, gray logo then kernel panic with jagged lines all across the shifted screen.