sdemott wrote:Because there seems to be a good deal of confusion and misinformation about basic Mac troubleshooting I thought I would try to shed some light on this often obfuscated process.
Why trust me? I used my first Mac in September of 1984...and those who remember that first Mac know you had to "fly solo" when it came to problems. Because of my early adoption I became the "go to guy" for all my Mac using friends over the next several years. Then when word had spread enough and I was getting enough calls from people who heard about me "from a friend of a friend of a friend" I went into the consulting thing as a paid profession (in 1992). I had Apple certification all through the '90s, up until about 2003 when it was obvious that the yearly testing fees were growing to be more in the MS territory. I worked as a full-time IT guy in a marketing/ad agency for a few years. These days I primarily keep my consulting & web design to musicians, artists and related institutions so I can spend time writing & recording music.
The Simple Stuff
Repair Permissions
There is a lot of confusion & misinformation about this simple maintenance procedure. Here's the real deal. When you repair permissions a comparison is made between an installs current state and the requested state from its install receipt. When they differ, they are changed to reflect the requested state.
In theory any installer that places a receipt in the proper place with all the proper user/permissions information can be repaired with a "Repair Permission" run. The unfortunate side effect is that companies tend to be reluctant to create a proper install package and usually forgo the extra work to include this information.
Receipts are stored in: /Library/Receipts/
When should you repair permissions? Anytime and every time you do any install or modification that requires you to enter your password. By the simple fact that an administrator's password is being asked for you are being warned that your file system is being altered. Always be sure to Repair Permissions to insure the filesystem is in its proper state after these tasks.
Preferences
From the early days of the Mac up to now there has been a common thread in troubleshooting - preferences corrupt themselves on a regular basis. To this day, I would say that about 90% of Mac oddities can be linked to a corrupt preference file.
The first step in troubleshooting an issue where something suddenly begins acting weird, or applications suddenly become unstable, should be deleting all related preference files. Keep in mind you will need to reset your application preferences after deleting preference files because they will revert to their default settings. But this is only for the application for which you removed the preference files.
Also, if you have the issue where you login and the login window hangs or the desktop hangs as the account first comes up, you most likely have corrupt LoginWindow.plist & LaunchServices.plist files. Check both preference locations for these files, delete & reboot.
Preferences are stored in: ~/Library/Preferences/ (user specific settings) & /Library/Preferences/ (system specific settings)
Advanced Stuff
Non-Volitile RAM (NVRAM)/Parameter RAM (PRAM)
When something goes wrong with these you will get power issues (systems that sleep without warning or won't wake from sleep), odd keyboard & mouse behavior or even odd display (on screen) anomalies.
You can reset the NVRAM/PRAM 2 ways:
Restart the system and hold down the cmd-opt-p-r keys until you hear 3 startup chimes. Release the keys after the 3rd chime and you will startup normally.
Restart the system and hold down the cmd-opt-o-f keys. When you see text come up on the screen welcoming you to Open Firmware release they keys. You will be at a text prompt (a ">" sign). Type the following:
>reset-nvram (pressing return will result in an "ok")
>set-defaults (again, press return for the "ok")
>reset-all (pressing return will reboot the system)
This only works on "New World ROM" PPC machines (G3s and better) and will not work on the new Intel Macs.
FileSystemCheck (fsck)
When things go really wrong you will want to check your hard drive for damage. You can boot from you Mac OSX install disk and run Disk Utility > check disk, but that always seemed like a good deal of extra work to me (because I'd have to find the CD and wait through a boot from the system on the CD - which always seems like it takes 100 years to complete). Instead, you can accomplish the exact same thing by dropping into Single User Mode and running a FileSystemCheck. The Disk Utility > check disk is a GUI for the fsck command.
Reboot and hold down cmd-s
Release when you see text appear on the screen with some gobbledy-gook about timeslicing, IODevice, the regents of the University of California at Berkeley and "the filesystem is mounted read only, fsck not done". You will find yourself at a command prompt (a ">" sign).
Type:
>fsck -fy (hit return & wait)
The system will check itself giving you a "play by play" of what's being done and if it has found any errors. If it does find errors it will warn you and then attempt to repair them.
Keep running the "fsck -fy" until you get the "disk seems to be ok" message.
After the "ok" message type:
>reboot
to boot back into the normal OS.
Standard Disclaimer
In closing, remember that you do not have to be comfortable with the tech end of a computer to use one for your day to day work. It is never a bad thing to develop a relationship with a local Mac consultant who understands the idiosyncrasies of a DAW setup. Many of them are musicians too and may even barter their services for some recording time. Playing around in Open Firmware and Single User Mode can be dangerous, and if something unexpected happens you can do serious/irrepearable damage to your system or files. Just because I am revealing these troubleshooting secrets does not mean I take any responsibility for their use or any damage they may cause to your system or data. Follow these instructions at your own risk.
You have been warned (and, hopefully, enlightened).