Repeatitive kernel panics on my quicksilver g4!!!

Question

can anyone help me with this problem? here is my system:
dual 1 ghz g4
1.5 ram
orig 64mb vid card
orig 80 gb hd
reinstalled OS X 10.4
here is what the panic.log says:
Unresolved kernel trap(cpu 1): 0x300 - Data access DAR=0x000000001F3CD0D0 PC=0x000000000030656C
Latest crash info for cpu 1:
Exception state (sv=0x37D36780)
PC=0x0030656C; MSR=0x00009030; DAR=0x1F3CD0D0; DSISR=0x40000000; LR=0x0027E890; R1=0x21FD3DE0; XCP=0x0000000C (0x300 - Data access)
Backtrace:
0x0027E858 0x0027E560 0x002A8174 0x000ABA30 0x43496E74
Proceeding back via exception chain:
Exception state (sv=0x37D36780)
previously dumped as "Latest" state. skipping...
Exception state (sv=0x37D6F000)
PC=0x90031010; MSR=0x0000D030; DAR=0xA0011A38; DSISR=0x0A000000; LR=0x00002ACC; R1=0xF00809A0; XCP=0x00000030 (0xC00 - System call)
Kernel version:
Darwin Kernel Version 8.0.0: Sat Mar 26 14:15:22 PST 2005; root:xnu-792.obj~1/RELEASE_PPC
panic(cpu 1 caller 0xFFFF0003): 0x300 - Data access
Latest stack backtrace for cpu 1:
Backtrace:
0x00095564 0x00095A7C 0x00026838 0x000A8184 0x000AB880
Proceeding back via exception chain:
Exception state (sv=0x37D36780)
PC=0x0030656C; MSR=0x00009030; DAR=0x1F3CD0D0; DSISR=0x40000000; LR=0x0027E890; R1=0x21FD3DE0; XCP=0x0000000C (0x300 - Data access)
Backtrace:
0x0027E858 0x0027E560 0x002A8174 0x000ABA30 0x43496E74
Exception state (sv=0x37D6F000)
PC=0x90031010; MSR=0x0000D030; DAR=0xA0011A38; DSISR=0x0A000000; LR=0x00002ACC; R1=0xF00809A0; XCP=0x00000030 (0xC00 - System call)
if you anyone can understand this please help! thanks in advance to this great community!!!

Answer 1

Angelo:
I just resolved the problem on my QS2002:
I realized that the one thing I hadn't swapped out was the fan, specifically the one that pulls in the cold air and blows it over the CPU. I knew it was working, so it never occurred to me that it may not be working well enough. The OEM fan has a thermistor on it: a small resistor that changes its resistance based on temperature. This in turn regulates the speed of the fan. Well, I hopped down to the closest computer store, picked up an $8 fan without a thermistor (meaning it runs at 100% all the time) and installed it. Lo and behold, the machine has been stable for over 2 days; with the original fan I was lucky to keep it up for 15 minutes.
This model of G4 does not have built-in temperature sensors that can be monitored via software, so there's no telling how hot it was running. Also, the overheating issue explains why all hardware tests came back clean, all component swaps had no effect, and reinstalling the OS did nothing as well.
One note of clarification: the machine wasn't kernel panicking in the traditional sense with the dimmed screen and the "you need to restart your computer" message. It was freezing hard: clock stopped, no mouse movement, etc. Every other time, with every other machine, I've always had the "traditional panic", regardless if it was a software issue or a hardware issue (bad USB device, etc.) Based on my experience, I'm now led to believe that this behavior is indicative of a CPU problem: either a bad CPU or an overheated CPU.
So try swapping out the fan. And be sure that you install it the right way: the CPU fan (it's in a rubber bracket that is attached to the motherboard door, that vents through the G5-esque grill near the USB & Firewire ports) pulls cold air in. The replacement fan you buy should have arrows on it indicating which way the air will blow.
Hope this helps,
- Mike
Quicksilver G4 (2002 Dual 1GHz)   Mac OS X (10.4.9)