Troubleshooting a Mac – Boot Options
Every once in a while a Mac gets so messed up that it won’t even boot. It’ll sit at the Apple screen, turning away. Or it’ll kernal panic just as it hits the blue login screen.
From Apple’s Support Knowledge Base here is what you need to do.
Resetting PRAM and NVRAM
1. Shut down the computer.
2. Locate the following keys on the keyboard: Command, Option, P, and R. You will need to hold these keys down simultaneously in step 4.
3. Turn on the computer.
4. Press and hold the Command-Option-P-R keys. You must press this key combination before the gray screen appears.
5. Hold the keys down until the computer restarts and you hear the startup sound for the second time.
6. Release the keys.
Your computer’s PRAM and the NVRAM are reset to the default values. The clock settings may be reset to a default date on some models.
If you have an older PPC Model Mac such as a G5 or Powerbook there is an additional step which will help.
Boot into Open Firmware by holding down the ‘Command-Option-O-F’ keys from a cold start while the chime is being played. You will see a command-line screen…enter these commands:
1. At the Open Firmware prompt, type: reset-nvram
2. Press Return.
3. At the Open Firmware prompt, type: reset-all
4. Press Return.
0 > reset-nvram
0 > reset-all
The reset-all command should cause the computer to restart. If this occurs, you have successfully reset the Open Firmware settings.
OSX 10.5.7 Update Issues
It’s comforting to know that when Apple screws up, they do it but good.
Not since the days of Tiger has a dot release from Apple done so much damage. On the surface, 10.5.7 is a very important update. A lists of fixes includes the usual round of security fixes, fixes for network performance, updates for Camera RAW support, among several other fixes. But, initially the Software Update version was throwing up errors “digital signature for the package is incorrect.” Apple rapidly fixed this but it underscores the importance of having good backups and a clean file system.
Afterwards, others started reporting BSOD or Blue Screens of Death after the update was done. Having originated on Windows, the BSOD is now available in Leopard, a nice, if unintended bonus from Apple.
Luckily this problem seems to be fairly easy to fix:
Wait for Hard drive access to stop
Hold Power button down until computer shuts off
Hold shift button down and power computer on to boot into safe mode
Use regular user name and password to login if asked
type reboot to reboot the computer
The next issue to commonly pop up is messed up display resolutions for non-Apple monitors. People are finding themselves stuck in 1920×1080! Resetting the PRAM (Hold down the Command, Option P and K keys while booting until it chimes three or four times) seems to fix for some.
For some of us REALLY unluckily people, the update gets stuck part way. After letting it sit for an hour at 33% there was no choice but to reboot the computer. Upon booting back up, OS X is not able to fully boot up. In one machine I was able to fix by going into safe mode, then issuing the softwareupdate -l -a command to finish the download and install.
On my Macbook, it was a full reinstall.