G5 Quad is dead
Posted by Pierre Igot in: MacintoshSeptember 10th, 2006 • 3:06 pm
Well, after many twists and turns, I think I can say with reasonable certainty that my 10-month old G5 Quad is now truly dead. Here’s a quick recap of what happened.
I bought my G5 Quad back in late November 2005. The machine included 512 MB of RAM, a 250 GB hard drive, and AirPort and Bluetooth connectivity. I immediately added 4 x 1 GB of third-party RAM (Samsung brand) and a second internal hard drive (Seagate 500 GB). Later on, I replaced the G5’s 250 GB hard drive with another Seagate 500 GB hard drive. Along with the G5 Quad, I also bought a 30″ Apple display, and began using the G5 Quad in a dual-monitor set-up with the 30″ display as the main monitory and a 23″ Apple display as the secondary monitor.
In January 2006, I got the G5’s video card replaced under warranty, because I was getting some annoying artefacts on the secondary screen. The video card was replaced under warranty by an authorized repair shop, and the artefacts vanished.
After that, the computer worked fine for about 8 months. I had some recurring problems, but they were mostly software issues with Mac OS X itself or third-party software, and not hardware issues. I always kept it up to date with all the latest system software updates.
About one month ago, my G5 Quad started experiencing freezes and kernel panics on a regular basis. When I say regular basis, I mean every 48 hours on average—sometimes less frequently, sometimes more frequently. After some basic troubleshooting steps (zapping the PRAM, etc.), I got on the phone with Apple, and the first step recommended to me was to remove all USB and FireWire peripherals, except for the mouse and keyboard. I did that, and still experienced freezes.
Instead of getting back on the phone with Apple right away, I did what any reasonably experienced Mac troubleshooter would do. I tried to eliminate potential causes. One of the first suspects was the third-party RAM I had added. I ran the G5 Quad on only 512 MB of RAM for a few days, which was a rather painful experience, especially until I turned off some third-party utilities I was using.
With only 512 MB of RAM, I didn’t get any freezes for about four days. This seemed to confirm that the RAM was the problem. I then tried to identify the defective RAM module. Since the G5 Quad requires RAM installed in pairs, I tried various combinations of 2 1 GB modules in addition to the default 512 MB of RAM. I also ran the memtest utility on three of the four RAM modules. The memtest battery of tests didn’t identify any problems with the RAM modules. But I tried all six possible combinations of two RAM modules, and I still got freezes or kernel panics each and every time, usually within a few days. (I once went six days without problems, but then got a kernel panic just the same.)
At that stage, I started to suspect that the problem was not the third-party RAM. It is, after all, rather unlikely that several different RAM modules would become defective all at the same time. It was also quite possible that the reason why I didn’t get a freeze with the default 512 MB of RAM was that I didn’t wait long enough. Out of curiosity, I tried running without the 512 MB of RAM and with only the third-party RAM. I still got freezes. I also tried turning AirPort off altogether on the machine, and using an Ethernet connection to my LAN itself. I went five days without a freeze, but then the machine froze again. (For the record, I am not distinguishing between freezes and kernel panics here, because when they happen while I am away from the computer, it’s impossible to tell whether it was a freeze or a kernel panic. In both cases, after a minute or two, the fans start running at full speed. Since my monitors are asleep most of the time when I am away from the computer, I cannot tell whether the screens are frozen or there is the kernel panic overlay. In any case, I once got a freeze where Mac OS X started drawing the kernel panic overlay, and then froze after drawing a few lines. So I suspect the difference between freezes and kernel panics doesn’t really mean anything here.)
Then yesterday (Saturday, September 9), I wanted to rip a few audio CDs—something that I hadn’t done in a while. For some reason, this caused the G5 Quad to freeze several times in a row. After a few freezes and hard resets, I had significant trouble even getting Mac OS X to run properly. So I booted from the system DVD and ran Disk Utility, which found errors on most of my hard drives (both internal and external)—which was not really surprising after all these freezes and hard resets of the past month or so. Disk Utility was able to repair all the disks, and I was able to restart the machine and get it to work normally again. But then I easily managed to make it freeze again by trying to rip more audio CDs. Eventually, I stopped ripping CDs and tried to do some work. The machine ran fine for the rest of the evening.
Then last night during the night, the machine froze again. I was woken up by the fan noise and went to my office to turn everything off and then went back to sleep. This morning when I tried to start the machine, it wouldn’t even start. I would get the normal grey start-up screen, but then I would get a black screen or Mac OS X would start switching the screens to blue but then freeze mid-way through. I tried booting from the system DVD, and that didn’t work either. The booting up sequence would just freeze after a while. Clearly something was very wrong now.
That’s when I noticed something physically wrong with the machine: there was a red glow around one of the digital audio ports on the back panel. I had never seen this before, but then usually when I look at the back panel it’s when the machine is off and I need to unplug the cables to get the machine out from under the table and open it up. So it’s quite possible that this red glow around the digital audio port has been there for a while (maybe even since the problems started a month ago) and that I just hadn’t seen it until now. Further testing showed that the red glow would not come as soon as I switched the G5 Quad on, but after the machine had started booting the system.
That’s not all. The G5 Quad also has a red LED somewhere on the front panel of the G5 Quad, behind the metallic grid. This red LED usually comes on, producing a red glow behind the grid, when the machine is frozen. But today, I noticed that the red LED in the front would also come on soon after turning the power on, and stayed on even while the machine was attempting to boot up.
In any case, I am no longer able to get this machine to boot at all. If I try to boot either from the startup volume on the internal hard drive or from the system DVD, the red glow in the front comes soon after turning the power on, and the red glow around the digital audio port in the back comes on later on during the booting sequence, before the machine freezes. It usually freezes just when it’s supposed to change from the grey startup screen to the blue background and start showing the progress window. When trying to boot from the system DVD, it freezes even before that.
I am, however, able to start the machine in FireWire target disk mode, and I can mount all the volumes via FireWire on my G4 MDD. I can copy all the files and do whatever I want with the volumes. So the problem is obviously not with the drives.
Out of curiosity, I restored the G5 Quad to its default configuration, with the 512 MB of RAM and the original 250 GB hard drive that I had kept on a shelf. I still get the same symptoms. Clearly something is very wrong with the computer, and more than likely with the logic board itself.
I sincerely hope that all these symptoms (freezes/kernel panics, red glow in back, red glow in front) are part of the same problem. But all I can do at this point is take the machine to the authorized repair shop and let them try to diagnose what’s wrong and repair it.
Unfortunately, going the repair shop is a six-hour round trip to the provincial capital Halifax. I had a trip scheduled this Friday (September 15) anyway, so I am going to try and make an appointment for Friday afternoon. I already have another trip to the city scheduled for the following Thursday (September 21), so I am really hoping that they’ll be able to identify and fix the problem between the 15th and the 21st. If not, I will have to make a third trip later on, I am afraid.
What this all means is that I have had to switch back to my “trusty old” G4 MDD, which I was using mostly as a test machine these days. I am certainly glad that I kept it instead of trying to resell it. Otherwise, I would definitely have been stuck. Unfortunately, this means that I have to switch back to my 23″ display as my main display (and a 17″ display as the secondary one), because the video card on the G4 doesn’t support the 30″ display.
I spent most of the morning copying all my documents and restoring a proper work environment on the G4 MDD, and that’s what I am using right now. It’s not awfully bad—it has 1.5 GB of RAM and three internal 120 GB hard drives. Running Mac OS X 10.4.7 on that machine is more than acceptable. It is certainly much better than trying to run Mac OS X 10.4.7 on the G5 Quad with only 512 MB of RAM!
Still, I am going to miss the extra screen real estate of the 30″ display and the extra hoompf of the fully functional G5 Quad with 4.5 GB. But I guess that things could be worse and I could be without a computer altogether.
Sadly, this turn of events confirms that I have now experienced major hardware problems with each and every machine that I have bought from Apple since 2001. This particular problem will obviously be covered by my AppleCare warranty, but the cost in lost revenue (all the time that I have spent troubleshooting this problem is valuable) and travel expenses is still substantial. Am I just particularly unlucky or is there a significant problem with hardware quality at Apple these days?
You decide…
September 10th, 2006 at Sep 10, 06 | 5:29 pm
Oh my! You seem to attract problems even more than I do.
I wish you good luck in getting it fixed quickly!
September 10th, 2006 at Sep 10, 06 | 6:01 pm
I’m sorry to hear about the issues. You certainly have had a run of problems.
The red LED, visible from the front, is usually related to a problem with the air deflector (the plastic see-through shield visible when you take the side off the case).
The red LED, visible from the back (near the DIMMs — I’m assuming this is the ony by the digital audio port, though I don’t know the layout of the Quads well enough to be sure) is also supposed to light only when some of the thermal ducting is removed. It’s there to remind you that the DIMMs are still powered if you take the case off and try to get at the DIMMs.
On the other hand, if it’s actually the audio port glowing, rather than a light on the motherboard that you can see coming out from behind it, then it’s nothing to worry about, it’s just the optical signal for the audio.
I’d advise double-checking any fan ducting and the air deflector, and making sure your fans are turning, as the main issue sounds likely to be thermal in nature, whether it’s actual overheating or an issue with the various bits of thermal management and monitoring the G5 does.
September 10th, 2006 at Sep 10, 06 | 9:44 pm
Dan: Thanks for your suggestions. The red light in the back is definitely in the audio port itself. But it still seems abnormal to me. I have never used this port, and i certainly have never seen it glow red. Admittedly, I haven’t often looked at the back of my G5 while it was running, but I think I would have noticed when plugging/unplugging FireWire or USB devices.
As for the red in the front, all I can say is that everything is definitely properly in place inside the machine, including the see-through shield. I’ve had to take the machine apart and put it back together more than once, to switch the RAM modules around, but I’ve always been very careful.
I’ve also kept an eye on all the temperature sensors during all that time, and haven’t noticed any abnormalities with the temperature (or fan noise). I can double-check everything again, but really accessing the RAM modules only involves 3 things: the outside door, the see-through shield, and the removable grey fan.
At this point I really do think that something’s wrong :). I certainly cannot get the machine to boot at all, either from the hard drive on from the system DVD.
September 11th, 2006 at Sep 11, 06 | 7:55 am
Well, Dan, what do you know… After posting my reply to you, I went back and fiddled with things a bit more. And lo and behold, I managed to revive the computer. The red light in the front is gone, and the machine can now boot from the HD. The red light in the optical port in the back is still there, though.
And of course I don’t know if the machine is still freezing or not. This is all terribly frustrating. I wish I had a way to reliably make the machine freeze.
September 11th, 2006 at Sep 11, 06 | 10:48 am
(This is a response to comment #3, not #4 — I tried to post it before I went to bed last night, but got a WordPress error.)
Oh, I don’t doubt that something’s really wrong; just figured I’d give you what information I had anyway. In dealing with getting a machine serviced, it’s always good to go in with as much knowledge as possible.
I’m quite certain the digital audio port is a red herring. (A red glowing herring, no less.) The glow from inside the port is the optical audio signal. I don’t know exactly what’s normal, but I believe it usually comes on during boot, then goes off later if no optical audio device is detected — it’s come up in some discussions because the Windows drivers on the Boot Camp driver CD don’t turn it off, so MacBook Pros and Intel iMacs have that light on all the time when booted into Windows. I know some MBP and G5 users have noted it being on for no obvious reason; whatever method it uses to auto-sense the presence of an optical cable seems to get overly eager now and again. It’s harmless, though.
In other words: if the other problems get fixed and the audio port is still glowing, I wouldn’t worry about it.
I hope your “local” shop gets you a quick and successful repair on this. Lord knows you’re due for a good customer service experience.
September 11th, 2006 at Sep 11, 06 | 11:09 am
This post might be of interest — there’s apparently a label on one of the tabs of the air deflector that can wear away, making the G5 think the air deflector is not installed, even though it is. This could be a contributing factor to the red LED, especially since you’ve been in and out of the machine repeatedly trying to diagnose the RAM.
However, the air deflector issue on its own shouldn’t render the machine unbootable; if it doesn’t detect the air deflector it should just light that LED and run at a reduced speed. So I’m still suspicious of something (else) thermal — whether it’s one of the sensors, or the liquid cooling pump, or one of the fans, or…
Have you been monitoring your system.log file with Console? There may be some clues in there, if anything is generating errors prior to the actual crash/freeze.
September 11th, 2006 at Sep 11, 06 | 2:54 pm
Dan: Thanks for all the additional information. (The WordPress error is due to a problem with connecting to the SQL server. It’s a problem with my host. I’ve complained about it and they have said they are working on it, but it still isn’t completely solved, as you experienced first-hand.)
You are probably right about the glow inside the optical audio port. I just talked to my colleague who has the same model (G5 Quad) and she says the red LED is on in the audio port on her machine too.
As for the red LED in the front, I looked at the page you linked to and experimented a bit. Indeed, when I remove the air deflector (see-through thing), there are two LEDs that come on, one red and one green, and the reduction in speed can be heard. I don’t think that was the problem I had yesterday, though, because
1) it really is quite difficult to put the G5 back together without putting the air deflector in properly; while playing with it just now, I saw that the LEDs were turned off as soon as the tabs went in, even before I actually pushed the air deflector all the way to put it firmly in place, so it looks to me like the tab sensor is quite sensitive and works quite well.
2) yesterday I only had a red LED, not a green one; it might have been the same LED (not sure if there’s another one in the same area), but the green one definitely wasn’t on.
And, like you said, having the air deflector off doesn’t prevent the G5 from running or booting. It just runs at reduced speed.
So it still looks like what happened yesterday was something different, but it’s quite possible that it has to do with thermal sensors. But I don’t know what I did that fixed it… or indeed if it’s fixed for good.
I did take a look at the system.log and it only has one sequence of stuff during the period when the G5 Quad was completely dead and I was not able to boot. That sequence reads as follows:
That’s all. That’s yesterday at 14:52, so it’s definitely when my G5 Quad was dead. I don’t know if it says anything significant.
As for the system.log during freezes, I’ve kept an eye on things in the past few weeks and I’ve never seen anything special in the log before the freezes or kernel panics.
Now my G5 Quad is running fine again. I put the 4 GB of RAM back in it, and it’s still running fine. I’ll have to see if it will freeze again in the next 48 hours or so. If it doesn’t, there’s no point in my trying to set up an appointment with the repair shop on Friday.
I should also note that, in anticipation of the trip to the repair shop, yesterday I removed the two internal Seagate HD and put back the original HD that came with the machine. This HD has an older system on it (10.4.5). If it doesn’t freeze with that HD, maybe the problem is actually a software problem with 10.4.7… (and maybe the problem I had yesterday with the machine not booting up was totally unrelated and just a thermal problem due to my constant fiddling with the machine).
Questions, questions, questions… I guess time will tell if the machine is really back from the dead or not. I tried to rip about 20 CDs with the machine this morning and it didn’t freeze once.
Thanks again for all your suggestions, and let me know if you see anything significant in the log above.
September 11th, 2006 at Sep 11, 06 | 9:04 pm
The interesting line from the log is “shutdown cause =3,” which should be the system management processor trying to report what caused the last abnormal shutdown. Unfortunately, I don’t know what cause 3 means and Googling it isn’t very educational. I’m out of helpful advice for now :-)
September 11th, 2006 at Sep 11, 06 | 9:51 pm
I have a G5 1.6Ghz Single CPU PowerMac running 10.4.7.
Couple of quick observations:
Optical port glows all the time on mine. I think this started happenning after some Apple update or other way back in the 10.3.x day’s.
Sometimes a little thing like a different brand of mouse can cause odd behavior on my PowerMac. I toss the odd behaving ones (eg Benq) & stick to known working ones (eg LogicTech).
ALWAYS install Apple Ram, It’s one less thing that they can use to dodge accepting responsibility for a warranty problem.
When I bought my machine it froze every hour or so, rang Applecare who then proceeded to ask insulting questions about “what have you changed” and when told nothing, it’s factory spec as supplied by you, they then promptly referred me back to the dealer for warranty service who then proceeded to smugly ask the same insulting questions about “what have you changed”. When told nothing, it’s factory spec as supplied by you, they did’nt have a leg to stand on. Interstingly they kept it for over 10 day’s until I got pushy about what’s taking so freaking long for christ’s sakes! No one would answer my question on the phone but when I turned up at the dealer was off handedly dismissed with “Oh your machine is ready, it was just the Ram…”
After taking the machine home (a four hour round trip) I found the machine totally unbootable. (A peek inside the machine showed totally mismatched ram chips) I rang the dealer who referred me back to Apple care all over again… Apple referred me back to the dealer again, this time the dealer accepted my call coz I had the repair authority from Apple (sigh).
Took it back to the dealer, waited another 5 business days for the dealer to do something. Had to front up at the dealer in person again & _demand_ they fix it. Turns out the machine was still sitting there untouched. Tech told me the usual speal about it’s in the queue. I waited until there were some other victims (err customers) in the shop then loudly demanded to see the manager. They appeared quite surprised at this request.
Explained to manager the sequence of events & demanded to know why they could not replace the ram chips on the spot. He reluctantly agreed & I got lots of strange “he’s a psycho” type looks from the staff. 30 min’s of waiting for them to “test” the ram chips I walked out with a working Powermac that has not missed a beat since.
I took over three weeks to get a working machine from the date of purchase.
No one could understand what all the fuss was about.
No one apologised, not Apple, not the dealer.
September 12th, 2006 at Sep 12, 06 | 8:57 am
Dan: Ah, the joy of numeric error messages. After all the years, even Apple still hasn’t managed to replace them with something actually useful…
Amavida: Pretty sad experience. My experience with Apple dealers is not all rosy either. With AppleCare, OTOH, things are usually better. I don’t know if it’s because I always introduce myself as a “Mac tech support person”. Maybe the dealers think I am competition for them, whereas AppleCare is just glad they don’t have to take me by the hand :).