G4 "Digital Audio" problems after 10.4.9 update

That icon with the slash means the OS experienced a kernel panic during startup, or experienced some other misc. issue. See http://docs.info.apple.com/article.html?artnum=106805.

If you have the space, I would first advise backing you up your system, or at least your personal data files, in case things get worse.

When you say there are errors being repaired, are these errors being reported from repairing the disk drive itself, or just the permissions?

If the drive your having problems with is internal, you can use Disk Utility to check the SMART status of the drive. Open that program, click on your hard drive icon in the list, and look near the bottom of the window. There should be a line that reads "SMART Status: " If the status indicates the drive is predicting it will soon fail, you will definitely want to backup your data and replace the drive.

Otherwise, you might try booting from your firewire drive again, and run the Mac OS 10.4.9 Combo updater against your main hard drive ( http://www.apple.com/support/downloads/macosx1049comboupdateppc.html). Sometimes an update of OS X does not install properly, and can be resolved by running the combo updater, which may replace bad/missing files that are preventing your system from updating.

Hope this helps, and good luck!

Another thought: Hold down command-v during startup. This trigger "verbose" mode when the OS is trying to boot. The output might appear cryptic, depending on your familiarity with OS X startup messages, but it may print more helpful information indicating what the problem is.

It's starting to sound that way sadly 😟

However, if you've invested in utilities like Disk Warrior, pop in that CD and allow to check your HDD. It might reveal directory structure corruption that's beyond fsck's (i.e. Disk Utility) ability to detect and resolve.

Also please check into my suggestion about verifiation of SMART hard drive diagnostics (in my previous post).

Another helpful utility if TechTool Pro. It can run advanced diagnostics on much of your hardware to ensure it's functioning normally, including a full sector verification of your hard drive(s). I've discovered bad disk blocks from this type of test in this past.

How much RAM do you have installed? If you have more than 1 stick of RAM, please try removing the one closest to the CPU, slide the others down the line, and keep an eye on things. If you have defective/marginal RAM, the OS might be corrupting itself in memory, leading to all kinds of potential problems. Memtest is a great tool to test RAM, but it recommends 5 passes which can take hours to complete: http://www.memtestosx.org/

If it comes down to simply being a corrupt OS X installation, one option you have is Archive and Install, which is a process Apple developed to allow users to make a best-effort at reinstalling the OS with minimal impact to already installed applications and user files: http://docs.info.apple.com/article.html?artnum=107120

Though doubtful, you might have an outdated version of Sonnet Cache installed (last release was April 2006, which includes support for OS X 10.4): http://www.sonnettech.com/support/downloads/osxupgradesw.html

Bear in mind I didn't look too deeply into Sonnet's information on this software and your processor. So I'm not sure if your processor even uses the Cache software or not. But if it does, you might want to try upgrading/reinstalling to the latest release. I'd be surprised if this fixed your problem, given how long you've probably been running 10.4.x

Good luck, keep us posted on your progress!

No problem, at least it's resolved now! Hopefully your troubles are over (for now.)