Recent Recommended updates jacked my iMac.

Question

UPDATES! Updates! This reminds me of why I converted to MAC from Windows; Updates would mess up my systems. That was years ago.
Zoom forward 15 years to 2 days ago when I installed the recent updates offered by auto-notification; this was never a problem in the past, so I felt safe to do so... after all... it's a MAC. YA?
Well, now, I reboot and reboot, I get squat,,, the system boots to the Apple icon, the screen flickers constantly and the iMac shuts down.
What's up with that?
So is this drive toast? Do I re-image? Is there a keystroke to by-pass?
DETAILS:  Before update attempt.
OSX-10.9.5
iMac (ITEL) 2007
4GB ram

Answer 1

Since you have 10.9.5 installed what were you updating? Do you see only the Apple icon or do you also see the rotating timer below it? Are you able to boot from your Recovery  HD?
Boot Using Command+R keys:
  1. Restart the computer.
  2. Immediately after the chime press and hold down the
      "COMMAND" and the "R" keys together.
  3. Release the keys when the Utilities Menu appears.
If so, then click on Disk Utility in the main menu and click on the Continue button.
Repair
After DU loads select your hard drive entry (mfgr.'s ID and drive size) from the the left side list.  In the DU status area you will see an entry for the S.M.A.R.T. status of the hard drive.  If it does not say "Verified" then the hard drive is failing or failed. (SMART status is not reported on external Firewire or USB drives.) If the drive is "Verified" then select your OS X volume from the list on the left (sub-entry below the drive entry,) click on the First Aid tab, then click on the Repair Disk button. If DU reports any errors that have been fixed, then re-run Repair Disk until no errors are reported. If no errors are reported then click on the Repair Permissions button. When the process is completed, then quit DU and return to the main menu. Select Restart from the Apple menu. If you still cannot boot the computer then you need to reinstall OS X:
Reinstall Lion, Mountain Lion, or Mavericks without erasing drive
Reinstall Lion, Mountain Lion, or Mavericks
OS X Mavericks- Reinstall OS X
OS X Mountain Lion- Reinstall OS X
OS X Lion- Reinstall Mac OS X
     Note: You will need an active Internet connection. I suggest using Ethernet
                 if possible because it is three times faster than wireless.
If your HDD fails to appear in the Disk Utility sidebar, then your drive needs to be replaced. If you cannot do the above repairs but the HDD is listed in the Disk Utility sidebar, then you need to reformat the drive and reinstall OS X:
Install or Reinstall Mavericks, Mountain Lion, or Lion from Scratch
Be sure you backup your files to an external drive or second internal drive because the following procedure will remove everything from the hard drive.
OS X Mavericks- Erase and reinstall OS X
OS X Mountain Lion- Erase and reinstall OS X
OS X Lion- Erase and reinstall Mac OS X
Note: You will need an active Internet connection. I suggest using Ethernet if possible
            because it is three times faster than wireless.