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PowerMac G5 frequent Kernel Panics

My Mac is a late-2005 model G5 Dual 2 GHz. Several months ago I upgraded from Tiger 10.4.11 to Leopard 10.5.8. Couple months later I started getting frequent Kernel Panics: Usually after running some maintenance software and a restart, but also after regular restarts (otherwise I leave my Mac on all the time), when couple hours later, always at night, I find the Mac shut down while the fans are loudly blowing at full speed.

I've alreday been running DiscWarrior periodically, as well as Cocktail. I also ran some hardware tests (DiscUtility, Drive genius, TechTool Pro) which found nothing abnormal with any of my hardware.

Based on what I've read, I checked my Console report, looking for "shutdown cause" and here's what I found next to each crash: (date, time) localhost kernel[0]: AppleSMU -- shutdown cause = 2 and I'm wondering what is the "2" meaning (the article I read was showing "3" as an example, though not explaining its meaning).

I'm already planning to open my Mac this weekend, reset the SMU (I understand my Mac has an SMU, not PMU), but before doing that, I'd like to know if anybody has an idea what is that cause = 2 meaning....

Thanks so much....

Power Mac G5 (Late 2005), Mac OS X (10.5.8), 5 GB Ram

Posted on Oct 10, 2012 9:13 AM

Best reply

Klaus1

Level 9

52,749 points

Posted on Oct 10, 2012 3:26 PM

What is a Kernel Panic?

http://support.apple.com/kb/TS3742

and http://support.apple.com/kb/TS1892?viewlocale=en_US

http://developer.apple.com/mac/library/technotes/tn2002/tn2063.html

More details here:

http://www.thexlab.com/faqs/kernelpanics.html

Useful article on how to avoid and eliminate kernel panics here:

http://reviews.cnet.com/8301-13727_7-10344626-263.html?tag=mfiredir

View in context

35 replies

Oct 13, 2012 3:14 PM in response to japamac

Here is one more detail that might shed some more light:

When I find the Mac's fan working loud and the screen dead, I push the power button to shut down, wait a few minutes (if it's in the middle of the night I just wait for the morning) and I try restarting again. But lately I'm having a hard time restarting, there's a RED LIGHT showing behind the power button while the fan starts running loud again, which is a clear sign of another crash (Kernel Panic?)...

...Could that mean something hardware-related? Could it be maybe the POWER SUPPLY, which — from what I've read — the (late-2005) G5 Mac had some issues with? Again, the Mac stays stable untill I perform a restart.... It crashes few hours later, and sometimes has a hard time restarting again.... As much as I can recollect, If I ZAP THE PRAM at startup (and usually I let it got thru 3-4 cycles) — it would startup OK.

......Can this help?

BDAqua

Level 10

239,435 points

Oct 13, 2012 3:22 PM in response to mynameismyname

How old is the PRAM Battery?

Oct 13, 2012 3:47 PM in response to BDAqua

...just replaced it with a new one some 6 months ago...

japamac

Level 7

24,400 points

Oct 13, 2012 5:05 PM in response to mynameismyname

there's a RED LIGHT showing behind the power button while the fan starts running loud again, which is a clear sign of another crash (Kernel Panic?)...

Not a kernel panic.

There are 7 diagnostic LEDs and two that are just there (no meaning).

About the Power Mac G5 (Late 2005) diagnostic LEDs

Oct 13, 2012 5:35 PM in response to japamac

Hmmm...... The white LED above the power button never flickers, and as far as the inside red LEDs, I sure won't be able to distinguish between them — but if all indicate my Mac needs service, I guess that's the next step needs to be........

Still, if in the middle of the night I find my Mac with its fan blowing crazy, while the screen is blank (white LED is on), and I shut it down -- THERE SHOULD BE SOME KIND OF A LOG THAT WOULD REPORT THE CRASH, NO? Kernel or no Kernel, it's still a bad crash, right? And I should be able to monitor what caused it, somewhere, no?

japamac

Level 7

24,400 points

Oct 13, 2012 5:57 PM in response to mynameismyname

I sure won't be able to distinguish between them

Open the side and look. It will be clear if you compare to the diagram in the linked article. Tell us which one and I can tell you what it means (more precisely than just seek service).

THERE SHOULD BE SOME KIND OF A LOG THAT WOULD REPORT THE CRASH, NO?

Not if it's not a crash. It could be a hang. It could be a wake from sleep issue caused by a connected USB device.

Kernel or no Kernel, it's still a bad crash, right?

It may not be a crash, just a freeze due to any number of possibilities. Overheat during OS routine maintenance, failure of a connected device to communicate, sleeping hard drive not waking, user settings in Energy Saver improper, etc., etc.

And I should be able to monitor what caused it, somewhere, no?

Monitor as in how? Read a log? Only if a kernel process is active and reports the issue.

You need to troubleshoot, not just look at it or hope something tells you "hey, I'm the problem".

9 times out of 10, the issue is ID'd not from logs, but from troubleshooting using the process of elimination.

Remove all external devices except keyboard, mouse and monitor.

Confirm that all your software is Leopard compatible and fully updated for Leopard. You did state that issues started after upgrading to Leopard....

OR, reinstall Tiger. That's the most stable OS for a G5.

Don't let hard drives sleep.

Set Processor performance to Automatic or even reduced.

Did you disable all third party maintenance software?

Did you troubleshoot startup and login items?

Did you troubleshoot your fonts?

Use a new user account to see if your settings are the issue. Don't adjust anything in the new user account. Use the default settings except in Energy Saver. Don't let hard drives sleep.

Oct 13, 2012 6:04 PM in response to japamac

Open the side and look. Tell us which one and I can tell you what it means (more precisely than just seek service).

So while the red lights show up I should move my Mac, open the lid, and the plastic shield, and look inside?... I guess since the HD is not rotating I can move my Mac out (it's in it's own "cage" hanging under my desk), right?

It could be a wake from sleep issue

No, I never let my HD sleep. Only my monitor.

Did you disable all third party maintenance software?

I just don't have any of them scheduled for any maintenance.

Did you troubleshoot startup and login items?

I deleted some "suspicious" login items.

...See, the problem is this crash is not consistent or persistent, it happens occasionally. It happened 2 days in a raw, then 2-3 weeks went by OK...

THANKS FOR YOUR HELP, JAPAMAC !

japamac

Level 7

24,400 points

Oct 13, 2012 6:20 PM in response to mynameismyname

So while the red lights show up I should move my Mac, open the lid, and the plastic shield, and look inside?...

Unless your eyesight is really bad, opening just the side panel should suffice. The air deflector (plastic shield) is clear....

See, the problem is this crash is not consistent or persistent, it happens occasionally.

Those are the hardest ones and the ones most likely to be software.

(it's in it's own "cage" hanging under my desk)

Huh? An external drive? The System Drive should be in one of the two bays in the interior of the machine.

A machine that runs from an external drive, especially if it is USB, WILL experience occasional hangs.

Oct 13, 2012 7:01 PM in response to japamac

Those are the hardest ones and the ones most likely to be software.

So it still might, or even likely be software, even if that red LED light shines on?

Huh? An external drive?

No, my Mac is seated in a metal "cage" that's hanging under my desk, but actually I might be able to move it just a little, in order to open the side panel and peep in.

Oct 16, 2012 11:26 AM in response to mynameismyname

...So last night -- another crash, after I did a restart earlier in the evening...

This time I picked my camera and took some pictures, so that we can isolate WHICH LED IS ILLUMINATING... But comparing this photo to the drawing you linked me to, japamac, it seems like the LED here is NOT ONE OF THOSE PLACED NEXT TO THE RAM (which is to the bottom right), it's much closer to the power button (this photo is cropped a bit, I have one with more to show, if needed)...

BTW, this morning when trying to restart again, again, I couldn't and the red light came on. I disconnected all my USB plugs (color printer that I stopped using long ago, which I should keep disconnected + my Canon scanner + my keybord & mouse), and it restarted OK. I now have only my keyboard & mouse connected.

ANY CLUES??????....... Thanks....

japamac

Level 7

24,400 points

Oct 16, 2012 2:56 PM in response to mynameismyname

it seems like the LED here is NOT ONE OF THOSE PLACED NEXT TO THE RAM

But it is just below the RAM, correct? Look at the diagram again. That is LED #7, is it not?

The meaning is a CPU hang, which is often caused by RAM. Download Memtest and test ALL RAM in Single User mode.

Another troubleshooting step when the #7 LED is lite is to reseat the processor. However, it seems that the final recourse with persistant hangs is to replace teh logic board. This is likely due to a failing memory controller or poor solder connections due to age, which can read like a failing RAM condition.

The only way to test the logic board is to get a copy of the ASD 2.6.3 and run the diagnostics.

Oct 16, 2012 4:46 PM in response to japamac

But it is just below the RAM, correct? Look at the diagram again. That is LED #7, is it not?

I don't think so... Look at a wider shot below (the original shot above was actually cropped from this one), the DIMS are to the right, quite further apart from this glowing LED.

japamac

Level 7

24,400 points

Oct 17, 2012 2:11 AM in response to mynameismyname

Apparently you don't know what DIMMs are.

DIMMs are the RAM (memory) modules.

The Late 2005 G5 has 8 DIMM slots, 2 banks of 4.

There are 4 RAM slots immediately above the glowing LED, with 5 other diagnostic LEDs at the immediate left of those slots.

There are also 4 RAM slots lower down that aren't included in your picture. The two heatsinks that are pictured (the meat tenderizer like objects) are positioned between the two banks of 4 RAM slots.

Make sure that your memory is installed properly.

The DIMMs must be installed in size matched pairs, poulating the innermost slots of the two banks first, with additional pairs moving outward:

http://support.apple.com/kb/HT2248

Oct 17, 2012 8:29 AM in response to japamac

YES, japamac, you're absolutely right and I was wrong (oye, I HATE admitting that ! 😝)....

See, when I opened the lid to take the picture it was in the middle of the night. I now opened the lid again in broad daylight, and of course, I now see where my DIMS are, 2 just above the lit LED, and 2 below (outside the photo)....

See screen capture below, I have a total of 5 GB RAM. I installed the additional RAM at least 3 years ago, and never tinkered with it since.

My questions are:

1. Do you see a problem with the SPEED difference between the 2 newer DIMS and the original ones (I bought the new RAM from OWC, which I consider reputable and dependable)?

2. Looking again inside my Mac, I see that the newer DIMS (with the "Crucial" label attached) are seated IN THE INNERMOST SLOTS, while the original ones are above and under (outward). Is there a problem here?

THANKS !!!

japamac

Level 7

24,400 points

Oct 17, 2012 2:21 PM in response to mynameismyname

1- Misreports are common, though not as with OWC RAM. Check with them.

2- Switch the RAM. Put the 512 MB DIMMs in the innermost slots.

PowerMac G5 frequent Kernel Panics