Sick Mac Pro Workstation

[Cartman]

Hope someone can help.

I have a 2012 Mac Pro workstation of the following spec.

4x 480GB SSDs
64GB RAM
2x Superdives
2x Graphics cards

All has been working well until today. When I try to boot the fans on the graphics cards go bonkers, the power light doesn't come on and a red light next to the RAM chips blink and then the computer when off. I removed the peripherals and no change.

I then removed the HDDs and checked them - they all work.

However, when I remove HDD bay 4 the system will boot into Windows. It will not however boot into Mac (Mountain Lion). Instead I get a grey screen with a no entry sign.

A search on the net hasn't helped and I;m hoping that someone here may be able to help me before I go speak to Apple.

 

[Kaveman]

A search on the net hasn't helped and I;m hoping that someone here may be able to help me before I go speak to Apple.

I assume you have a full backup, with a Mac like that I'd go to an AppleCare Service Centre, you may find a "non-Apple" one to have more time to spend on your problem.
If you have a Backup, you could do an OSX Install in place.

 

[Cartman]

Oh yes. Lots of backups!

It is a fairly new machine so it should be covered by the warranty. I rather thought it was a hardware problem on the SATA connections on port 4. Just odd that Windows boots but I guess Windows may not be as demanding about booting if a component has failed

 

[Kaveman]

I think what has happened, (shot in the dark)
The SDD drives, 2nd Drive and 2 Graphics cards are exceeding the Power draw limit on the Power Supply, Did Apple Build this config?
When the Power supply tripped it crashed OSX and that is why it won't start.

You have 1 problem, power draw, that caused a second problem, crashed OSX...

 

[Cartman]

Ah. Now that's a possibility. Apple built it with one SSD, both cards and the RAM and I added the other three SSDs. I will try pulling one of the graphics cards. Any idea why Windows will still boot though?

 

[Kaveman]

You have 1 problem, power draw, that caused a second problem, crashed OSX...

Windows may not have been in a risky state when it crashed. There is always a reasonable chance of modern OSs not booting if they get an unexpected power out. It broke OSX this time.