Q: Mac Pro HD and Startup Woes ... AGAIN!

We can guess yours is a 2008 3,1 or later, that is all. No sign of what model.

General purpose Mac troubleshooting guide:

Mac OS X: Starting up in Safe Mode - http://docs.info.apple.com/article.html?artnum=107393

What is Safe Boot, Safe Mode? (Mac OS X) - http://support.apple.com/kb/HT1564

Isolating issues in Mac OS X

Creating a temporary user to isolate user-specific problems:

Isolating an issue by using another user account

Identifying resource hogs and other tips:

Using Activity Monitor to read System Memory and determine how much RAM is being used

Starting the computer in "safe mode":

Mac OS X: What is Safe Boot, Safe Mode?

To identify potential hardware problems:

Apple Hardware Test

General Mac maintenance:

Tips to keep your Mac in top form

Recovery Mode

http://support.apple.com/kb/HT4718

TimeMachine 101

https://support.apple.com/kb/HT1427

http://www.apple.com/support/timemachine

Mac OS X & Mountain Lion Community

https://discussions.apple.com/community/mac_os

https://discussions.apple.com/community/mac_os/os_x_mountain_lion?view=discussio ns

Create an OS X Lion Install disc

Migration Assistant Update for Mac OS X Snow Leopard

http://www.apple.com/support/lion/installrecovery/

http://reviews.cnet.com/8301-13727_7-20080989-263/how-to-create-an-os-x-lion-ins tallation-disc

http://www.coolestguyplanettech.com/how-to-make-a-bootable-osx-10-8-mountain-lio n-disc-or-drive-from-the-downloaded-mountain-lion-app/

How to clone your system:

http://macperformanceguide.com/Mac-HowToClone-backup.html

http://macperformanceguide.com/Mac-HowToClone.html

http://www.macupdate.com/app/mac/7032/carbon-copy-cloner

http://www.macperformanceguide.com/blog/2012/20120711_2-MacPro-internal-clone-ba ckup.html

Before you clone, install TRIM Enabler!

boot in Safe Mode, (holding Shift key down at bootup; takes longer to boot this way so be patient), run Disk Utility in Applications>Utilities, then highlight your drive, click on Repair Permissions, reboot when it completes.

Mac OS X: Starting up in Safe Mode - http://docs.info.apple.com/article.html?artnum=107393

What is Safe Boot, Safe Mode? (Mac OS X) - http://support.apple.com/kb/HT1564

Safe Boot takes longer than normal startup - http://docs.info.apple.com/article.html?artnum=107394

I recognized your name but not the old thread.  3TB drives are trouble for some users, some make/midel. Dont say 3TB but WD Green, Seagate 7200.15 or some specific, even link to vendor or where bought.

3TB is not a good choice for a system drive.

Green are okay for backup duty. And you can use part for TimeMachine and other volumes to clone another drive -- once all the data recovery was done AND intact and you ran one or two file integrity checks - Dlloyd sells one that is probably very reliable, or by cloning with CCC as I said.

Take everything out but the boot drive and data drive and run with that. And put the green 3TB in external case.

Once you have: live data drive(s), clone of each live volume somewhere safe, at least one good (started over) TimeMachine, you should be good to go.

I'd keep the recovery drive as is for awhile.

The fact that you had so much trouble AND crashed or quit or lost Disk Warrior rebuild at one point means any files and directory are "suspect" until you feel safe and otherwise.

TechTool Pro 7 for safety investment $100 towards reliability. $140 for SoftRAID 4 to manage your drives and alert if there are I/O errors occuring or read errors or bad sectors (they are not black and while "good/bad" they can be weak too).

I use this though there are plenty of others for a nice external drive

http://www.amazon.com/gp/product/B00545ZA92/

http://www.amazon.com/WD-Green-Desktop-Hard-Drive/dp/B008YAHW6I/

Why would there be NO response to any key commands?

Unless the keyboard is plugged into a USB directly on the chassis, the Hubs (e.g., in USB ports on a display) often come up too late for these power-on "snag keys" to be seen.

Take the suspect out of the equation.

That is "101" for testing any theory.

A causes B but only in the presence of C

A hard drive sector or directory or cable or other hardware is at play.

I had a drive case block booting on one computer until I could do more to isolte the vase or drive or bad sector etc and was fine afyerwards

3 way pass by Disk Utility took overnight

WD LIFEGUARD was more reliable but also toook 3 hrs

On wired USB keyboards, I have never had a problem with holding the keys down the entire time. I suspect the waiting approach is needed for wireless keyboards -- to be there after they are active, but not too soon to get the keystrokes discarded.

The least hardware-intensive operation is the Alt/Option key, to invoke the Startup Manager, because its code is all in ROM. It can get you almost everywhere except the diagnostic or PRAM Reset.

http://macperformanceguide.com/Storage-Drive-Hitachi-7K4000-4TB.html

New updates today about 3 and 4TB drives.

http://macperformanceguide.com/

RED are not supported in a Mac Pro and are best used in NAS or Hardware RAID. ie Hardware RAID controller.

[WD] RED are not supported in a Mac Pro

I did not know that. What makes them unsuitable/unusable?