Mac pro OS X 10.6 Snow Leopard won't boot after software up-date

Question

I am new to Apple/Mac products. I recently bought an iPad and liked it so much mt epiphany was that this must be why Mac users are so loyal to Apple products. So I bought a used Mac Pro on EBAY, received the unit in good condition, set it up and booted. after I got it online I discovered it was due for a software update. No problem. I followed the software update icon, downloaded 4 updates and began the 2 hour download. When the download completed I clicked to install and left the room. when I returned the screen was blank. I grabbed the mouse in an attempt to "wake it up". The fans kicked on and it sounded like a jet taking off bot the screen remained blank. It has not booted since. Any ideas on how to recover?

Answer 1

Me: bought off ebay? then take the DVD OEM discs and clean system install.
Upper right  corner "About this Mac..." More.... takes you to System Profiler.
Top lines of what model etc. do not include serial number but you might want to call and / or check that too and order replacement DVDs if it didn't have those.
but for now, Wipe the drive.
You can backup first if you want.
Utility folder: Disk Utility: Restore: allow drag and drop the source and target.
www.macupdate.com "backup programs" I recommend Carbon Copy Cloner to maintain bootable backups and can also archive changes. Similar to what Paragon Manager Suite offers in Clone OS to SSD.
Boot from the OS X DVD it should have come with. Choose the Utilities from menu bar : Disk Utility to repair or format. Then go back and Install OS X.
Using Cloning as a Backup Strategy
http://www.macupdate.com/app/mac/7032/carbon-copy-cloner
http://www.bombich.com/software/updates/ccc-3.5.htmlOS X Lion Install to Different DriveHow to create an OS X Lion installation disc MacFixItMigration Assistant Update for Mac OS X Snow Leopard
http://www.apple.com/support/lion/installrecovery/ Create an OS X Lion Install dischttp://reviews.cnet.com/8301-13727_7-20080989-263/how-to-create-an-os-x-lion-ins tallation-disc
How to clone your system:http://macperformanceguide.com/Mac-HowToClone-backup.htmlhttp://macperformanceguide.com/Mac-HowToClone.htmlhttp://www.macupdate.com/app/mac/7032/carbon-copy-clonerhttp://www.macperformanceguide.com/blog/2012/20120711_2-MacPro-internal-clone-ba ckup.html
Mac OS X Help
Isolating Issues in Mac OShttp://support.apple.com/kb/TS1388
https://www.apple.com/support/osx/https://www.apple.com/support/quickassist/http://www.apple.com/support/mac101/help/http://www.apple.com/support/mac101/tour/
Get Help with your Product
http://docs.info.apple.com/article.html?artnum=304725
TimeMachine 101 https://support.apple.com/kb/HT1427 
Mac OS X & Mountain Lion Communityhttps://discussions.apple.com/community/mac_oshttps://discussions.apple.com/community/mac_os/os_x_mountain_lion?view=discussio ns
Recovery Modehttp://support.apple.com/kb/HT4718
reset SMC For "Mac wont' turn on or boot" and relatedhttps://support.apple.com/kb/TS1367
General purpose Mac troubleshooting guide: Isolating issues in Mac OS XCreating a temporary user to isolate user-specific problems: Isolating an issue by using another user accountIdentifying resource hogs and other tips: Using Activity Monitor to read System Memory and determine how much RAM is being usedStarting the computer in "safe mode": Mac OS X: What is Safe Boot, Safe Mode?To identify potential hardware problems: Apple Hardware TestGeneral Mac maintenance: Tips to keep your Mac in top form
First, if at all possible make a backup of the drive in its present configuration.  If something goes wrong during repair attempts and makes things worse you will have a backup.  You will have to decide how to work this in the light of any present backups you may have, for example, a backup that may be a few days out of date.  In that case you may want to keep that one and make a second backup of this as they are now, though I realize people often don't have a lot of empty drives sitting around.
Boot from the System Installer disc that came with your computer or is the one for the version you currently have on there, select language if applicable, choose utilities, run Disk Utility and verify (and repair if necessary) the drive. You can verify a drive from DU on your main drive while booted but I have found this can result in incorrect reporting of errors. To repair your drive you have to run it from a drive other than the boot drive anyway. Next, boot from your drive in Safe Mode (http://docs.info.apple.com/article.html?artnum=107393) and repair permissions.  You can repair permissions while booted from the installer disc but this uses the permissions configuration on the installer disc which may be out of date if you have run any updates on your computer.  Booting your computer to Safe Mode restricts the number of things running on your computer while permissions are being run and does a bit of spring cleaning at the same time.
Reading
Resolve startup issues and perform disk maintenance with Disk Utility and fsck - http://docs.info.apple.com/article.html?artnum=106214Using Disk Utility in Mac OS X 10.4.3 or later - http://docs.info.apple.com/article.html?artnum=302672Disk Utility's Repair Disk Permissions 10.0-10.6 - http://docs.info.apple.com/article.html?artnum=25751"Try Disk Utility" (modified from http://support.apple.com/kb/TS1417)
1. Insert the Mac OS X Install disc that came with your computer (Edit: Do not use this disc if it is not the same general version as what you have currently on your computer, e.g. use a Tiger disc for a Tiger drive, not a Panther disc), then restart the computer while holding the C key.
2. When your computer finishes starting up from the disc, choose Disk Utility from the Installer menu. (In Mac OS X 10.4 or later, you must select your language first.)
Important: Do not click Continue in the first screen of the Installer. If you do, you must restart from the disc again to access Disk Utility.
3. Click the First Aid tab.
4. Click the disclosure triangle to the left of the hard drive icon to display the names of your hard disk volumes and partitions.
5. Select your Mac OS X volume.
6. Click Repair. Disk Utility checks and repairs the disk."