I've got a 2008 Mac Pro (2x 2.8GHz Quad Core) running 12GB RAM, and dual (physical) OS drives (one running 10.6, the other 10.7).
Tried to boot the machine this morning, doesn't even make it to the Apple logo (the Apple chime does sound, just sits on a grey screen).
- Have checked both OS drives. The 10.6 drive had died over the weekend so that needs fixing, BUT the machine still fails to detect the other OS, which appears to be fully functional.
- I have tried an external OS on a portable hard drive to make sure that it isn't an internal OS drive bay issue, and same result.
- I have swapped the graphics card from an identical machine, and same result.
- I have swapped RAM using various combinations, and same result.
Running out of options. Any ideas? Was functional on Friday.
----------
Typically as I posted this my co-worker just told me the RAID card is the culprit. It had caused grief six months ago and so we've been running it without the RAID. Now it's obviously affecting the boot up.
Ignore this thread...

Tried to boot the machine this morning, doesn't even make it to the Apple logo (the Apple chime does sound, just sits on a grey screen).
- Have checked both OS drives. The 10.6 drive had died over the weekend so that needs fixing, BUT the machine still fails to detect the other OS, which appears to be fully functional.
- I have tried an external OS on a portable hard drive to make sure that it isn't an internal OS drive bay issue, and same result.
- I have swapped the graphics card from an identical machine, and same result.
- I have swapped RAM using various combinations, and same result.
Running out of options. Any ideas? Was functional on Friday.
----------
Typically as I posted this my co-worker just told me the RAID card is the culprit. It had caused grief six months ago and so we've been running it without the RAID. Now it's obviously affecting the boot up.
Ignore this thread...