My Troubled Mac – Part 2

The good – It boots and runs

The bad – One kernel panic, one freeze

The ugly – Difficult to isolate the problem


Yesterday, I started the process of evaluating and fixing My Troubled Mac. It’s an Apple G4 1.42 GHz Dual Processor FW800 MDD (Mirror Drive Doors) model that has been prone to frequent kernel panics and freezes. My goal is to isolate the source of these problems, then decide on a course of action.

I started by removing all the hard drives, a USB 2.0 PCI card, and the Apple Internal Modem card. I installed a single hard drive, which is known to be good. I then reset the PMU. I left the DVD drive, video card, and RAM installed. So I now have a basic hardware configuration for testing.

I formatted the hard drive, using Apple’s Disk Utility application on the (retail) Mac OS X 10.4 (Tiger) installation DVD. I then started on the long and time-consuming process of installing and updating the Mac OS.

After Tiger was initially installed from the DVD, I configured some basic parts of the OS. The most important of these was the network configuration, so I could connect to the Internet via my ADSL modem. This also enabled me to access the various Mac OS update installers I had previously downloaded, which were stored on another Mac connected to my network.

I followed the usual drill—run the Software Update application to see what updates I need to install, install them, then run Software Update again, install more updates, etc. Fortunately, there were only a few, very recent updates that I hadn’t already downloaded. After running Software Update a grand total of 13 times, it finally reported that everything was up to date.

At this point, the only issue was some video display artifacts. They went away after I installed the control panel and driver for my ATi Radeon 9600 Pro PC and Mac Edition video card. The ATi stuff is the only software I installed that was not part of the Mac OS installation and update process.

Throughout this process the Mac was behaving as expected. However, I really had done nothing more than install software, access the Internet and another Mac via my ethernet network, viewed a few web and text documents, and set some configuration settings. None of this activity put much stress on the Mac, but at least everything was stable.

Most of the kernel panics and freezes I had previously experienced seemed to happen when I was scrolling a window, most often in a web browser, both in Firefox and Safari. So I launched Safari and cruised the web, loading pages and scrolling the browser window, with no problems. I decided to try loading a web page that might be a little more demanding. Off to YouTube I went. I started playing a video and scrolling the browser window repeatedly, then…Boom! My web browsing experience was rudely interrupted with the (unfortunately) all too familiar kernel panic notification screen overlay. I power cycled the Mac and rebooted, tried a few other web sites, scrolling up and down the pages, then the system froze. It was getting late, so I shut down the Mac and went to bed.

Here is the panic.log report for the latest kernel panic. If anybody knows how to make sense of Apple’s panic logs, and can suggest what might be wrong with my Mac, I’d really appreciate it.

Sat Jul  4 00:16:49 2009
panic(cpu 1 caller 0x000A4EC8): simple lock (0x0038EFA0)
	deadlock detection, pc=0x0003C350

Latest stack backtrace for cpu 1:
0x000954F8 0x00095A10 0x00026898 0x000A4EC8 0x0003C350 0x0002EA6C 0x000ABEAC 0x805E200C Proceeding back via exception chain: Exception state (sv=0x45190000) PC=0x90033908; MSR=0x0200F030; DAR=0x371F8040; DSISR=0x40000000; LR=0x907F2540; R1=0xBFFFE130; XCP=0x00000030 (0xC00 - System call) Kernel version: Darwin Kernel Version 8.11.0: Wed Oct 10 18:26:00 PDT 2007; root:xnu-792.24.17~1/RELEASE_PPC

Today I’ve been using the Mac to surf the web, and create text documents. So far I’ve had no kernel panics or freezes. I really don’t understand what’s happening, but I’ll continue with my tests.

Follow my progress in Part 3.


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