Kernel Panic every 20 mins on Dual 2 Ghz G5

[videoterrorist]

Hi,
Hope someone can help...

Today for some unknown reason my Dual 2 Ghz G5, 1GB RAM, 10.5 is producing a Kernel Panic about every 20 minutes!!!

Here's the panic log, but I have no idea what I'm looking at to try find a solution:

Mon Dec 14 14:08:20 2009
panic(cpu 0 caller 0x000A0FF4): "mapping_alloc - empty mapping block detected at 0x1465c000\n"@/SourceCache/xnu/xnu-1228/osfmk/ppc/mappings.c:1172
Latest stack backtrace for cpu 0:
Backtrace:
0x0009AD18 0x0009B6BC 0x00029DC4 0x000A0FF4 0x000A12E0 0x0009E5AC 0x000642F0 0x00064858
0x00067D60 0x00071D54 0x00072038 0x00068584 0x0006867C 0x002B3738 0x002B3A2C 0x0030924C
0x000B24C8 0x00000000
Proceeding back via exception chain:
Exception state (sv=0x3b532780)
PC=0x91745BC8; MSR=0x0000F030; DAR=0xE04F3000; DSISR=0x42000000; LR=0x917836E0; R1=0xF0206980; XCP=0x00000030 (0xC00 - System call)

BSD process name corresponding to current thread: rsmac_3630

Mac OS version:
9A581

Kernel version:
Darwin Kernel Version 9.0.0: Tue Oct 9 21:37:58 PDT 2007; root:xnu-1228~1/RELEASE_PPC

Thanks in advance!

 

[videoterrorist]

I've now done a clean install of the OS, reset the PRAM and still she Panics!
The SMART status claims all is well, as does the RAM in System Profiler and the diagnostics.
I've read plenty about dodgy Ram causing panics, any ideas anyone?

 

[FireArse]

I've read plenty about dodgy Ram causing panics, any ideas anyone?

You've done the right thing so far - looks like the next step is component isolation. Pull out the optical drive, BT card & Airport card (if installed). Any PCI cards installed? pull them out.

On the two grey discs that came with the machine, a Hardware Test was provided - try that.

Next thing to try would be to get hold of RAM that you know 100% works. Perhaps RAM from Crucial? Or, if you're not too far from an Apple Retail store, explain to a Genius (before you go in with the Mac) you'd like to test RAM.

Chances are they won't have it in stock to try out, but if you ask them to 'SNR' (take your Mac's serial number) you x2 512MB you can try...

I had one of these babies - they are built so well - I'm guessing one of your RAM sticks has failed.

F