I installed Mavericks as an upgrade to OS X 10.6.8 on my iMac and with in a half an hour of use my computer froze, I have tried all the normal rebooting techniques but my opening screen still has the vertical green stripes, even after using the disk repair/first aid utility, the iMac freezes without fully booting. the disk repair found no issues and says all is OK.
iMac, Mac OS 9.2.x
Hello Tone56,
It sounds like you are unable to successfully boot your computer after upgrading to Mavericks, and are seeing some graphical anomolies on startup. I recommend starting by resetting your PRAM with this article:
OS X Mavericks: Reset your computer’s PRAM
http://support.apple.com/kb/ph14222
Note: To print these instructions, open Help Viewer’s Action pop-up menu (looks like a gear), then choose Print.
- Shut down your Mac.
- Locate the following keys on the keyboard: Option, Command (⌘), P, and R. You will need to hold these keys down simultaneously in step 4.
- Turn on your Mac.
- Immediately press and hold the Option-Command-P-R keys. You must press this key combination before the gray screen appears.Continue holding the keys down until your Mac restarts, and you hear the startup sound for the second time.
- Release the keys.
Resetting PRAM may change some system settings and preferences. Use System Preferences to restore your settings.
Then reset your SMC:
Intel-based Macs: Resetting the System Management Controller (SMC)
http://support.apple.com/kb/ht3964
Resetting the SMC for Mac Pro, Intel-based iMac, Intel-based Mac mini, or Intel-based Xserve
- Shut down the computer.
- Unplug the computer's power cord.
- Wait fifteen seconds.
- Attach the computer's power cord.
- Wait five seconds, then press the power button to turn on the computer.
If the issue persists, try performing a Safe Boot then restart as normal to see if that will allow you to boot normally:
OS X: What is Safe Boot, Safe Mode?
http://support.apple.com/kb/ht1564
Starting up in Safe Mode
To start up into Safe Mode (to Safe Boot), follow these steps.
- Be sure your Mac is shut down.
- Press the power button.
- Immediately after you hear the startup tone, hold the Shift key.
The Shift key should be held as soon as possible after the startup tone, but not before the tone.- Release the Shift key when you see the gray Apple logo and the progress indicator (looks like a spinning gear).
After the logo appears, you should see a progress bar during startup. This indicates that your computer is performing a directory check as part of Safe Mode.
To leave Safe Mode, restart your computer without holding any keys during startup.
Thank you for using Apple Support Communities.
Cheers,
Sterling
thanks Stirling I have tried all of the things you mentioned, the next step is to reformat, but I think my graphic card is cactus. I am operating in safe mode untill I get a new portable terrabyte hard drive. I have contacted Apple support here in Oz and they have been helpfull I Have already paid to have a new graphics card installed so this would be the second. and seeing as I don't have any games or watch movies on my Mac (it's primary use is for music) I fear my mac has an underlying problem that I am hoping Apple will fix. Lets face it a graphics card should last longer than a couple of years. my now ancient PC has a Nvidea card that sill works after 15 years as does the old soundblaster card. So methinks there is a problem
iMac wont start up after upgrade to Mavericks
