PowerMac G5 Dual 2GHz freezes any time, boots sometimes with one processor

I've put everyting back after cleaning it, specially the PSU and luckuly I didn't mess up anything.
But, the problem still persists. When I turned it on, it booted!, but as I was about to install Hardware Monitor, the G5 Crashed. I restarted it and did an 'Extended' Apple Hardware Test using the Tiger CD, it tookabout 45mins to complete and the result was that there are no Hardware problems to report.

I booted the computer and it booted fine again, by this time it was past midnight so I just turned it off and went to sleep.

The next day I turned it on at 8am and installed Hardware Monitor and left. When I came back at 12noon the fans were at full speed and the screen was black, I forgot to disable the sleep mode, so it probably went to sleep and then fans went crazy during the sleep. The sleep settings were set to 3hours for both; computer and screen with a check mark on 'Put the harddrive to sleep whenver possible'.
The 'Processor Performance' option I had it to Automatic.

Restarted it again and got the freeze logo, I tried to do the Extended AHT again but it froze halfway during the process.

I have finish doing another Extended AHT and after it was done, it said that there were no hardware problems to report.

But I notice something different from this test and the first one I did. The difference was on the 'Hardware profile' tab.
The previous times under CPU it showed a number '2' now it shows '@1702037.8Ghz'

I'm trying to boot again and I just keep getting the frozen apple logo.

So i guess I'm now having the same problem as you Drew, where only one CPU comes up.
During these few times that the computer have booted, I've checked under 'About this Mac' and 'More info' and it showed a 2 under 'Number of CPUs'.
Since now is not booting, I don't know what it will say now that it showed "@1702037.8Ghz" for CPU in the AHT.

This is what I get everytime I do a Apple Hardware Test 'Extended Test'
http://img508.imageshack.us/img508/2021/g5cpu3ok0.jpg

This is what came up on the Apple Harware Test 'Hardware Profile' (quiality is bad because it's a video frame not a picture, but notice where it says CPU and compare it to the photo on the last link)
http://img263.imageshack.us/img263/1166/g55rz0.jpg

This is what I got on the System Profiler when my G5 booted.
http://img93.imageshack.us/img93/7335/g5cpu2yn7.jpg

This is what Hardware Monitor showed when the G5 Booted.
http://img110.imageshack.us/img110/5893/g5cpuwt9.jpg

Now that the G5 doesn't boot, this is what it comes up on the Apple Harware Test 'Hardware Profile'
http://img110.imageshack.us/img110/6672/g5cpu4zx3.jpg

It seems to me the these freezing apple logo and/or the black screen when booting might be due to a deffective processor(s). I could only test this theory if I had 2 spare processors but I don't. I've been looking around and the average cost is $300 per processor.
I think the Logic Board, PSU, HD, Memory and everything else is fine, the problem at least on my case is within the Heat Sink/CPU units A, B or both.

Hi Tenoch,

Looks like the prices for new ones vary widely: http://www.dvwarehouse.com/Power-Mac-G5-Processor-c-2532381434.html

Edit: Not new, used.

Message was edited by: Samsara

I went to the genius bar & explained that the processor had died, and my Applecare had expired 2 months ago. I also showed the 'genius' the photos of the cooked PSU resistors - which he asked if they were capacitors. He didn't think my 'cooked' PSU would be able to knock out a processor.

He didn't seem too interested in finding out all the tests I had done - fair enough really, tech support shouldn't trust the word of random people.

I explained I had the 'Service Source' manual and the 'Apple Service Diagnostic CD' and he said I shouldn't really have them, well I got the CD image from the Apple support site so that is not my fault. My access permission to this area of the Apple site has since been revoked - thanks forum moderators.

He said I had invalidated my warranty by removing the PSU and other components and because the Applecare had expired my only option was to pay for diagnostics. It would either be around £40 or £70, depending on if the processor was at fault or if it was the logic board.

Once the diagnostics have been completed then it would be a question of replacing the processor or logic board I think they were £450 for the Logic board and £750 for the processor.

I'm not sure I want to spend any more money on this mac to be honest. It would be nice to get it working, but the cost of parts is close (or more) to a new mac Mini. I'm starting to feel that the PPC macs are sluggish compared to the Intel models.

I'm really unsure where to go from here Tenoch T. How far did you go at stripping the G5? I'm wondering if getting a look at the rear of the logic board may reveal any clues to this issue.

I also wondered about removing the heat sink from the processor and reapplying it, but that thought really scares me.

Those hardware tests are quite odd Tenoch T, my AHT has always failed on the video tests even when new, I have an ATI 9650 graphics card.

I guess the simplest thing to do is to take it in to the Apple store & let 'em diagnose it, but sadly they can't promise that the results will be the only thing wrong with it.

I've been seeing similar issues for WEEKS now.

I've reset nvram, shut down one of the cpus via terminal, I've swapped out drives, went down to 1 set of ram - I've even cleaned and dusted out the ENTIRE computer, PSU, and reseated both the CPU modules/reapplied thermal paste.

The most success I've had is disabling 1 CPU - but even then eventually the computer will freeze on some mouse action or another (doesn't matter whether I'm using the original keyboard/mouse combo or bluethooth keyboard)

I was able to recover the following panic log:

panic(cpu 1 caller 0x000A4EC8): simple lock (0x003DA020) deadlock detection, pc=0x00033564

Latest stack backtrace for cpu 1:
Backtrace:

backtrace terminated - frame outside of RAM: v=0x37892A50, p=00007DAA

Proceeding back via exception chain:
Exception state (sv=0x5FD47780)
PC=0x000AF53C; MSR=0x00009000; DAR=0xF0182EC4; DSISR=0x42000000; LR=0x000340A8; R1=0x473A3E30; XCP=0x00000024 (0x900 - Decrementer)
Backtrace:

backtrace terminated - frame outside of RAM: v=0x473A3E30, p=00105E87

Exception state (sv=0x5F4E2280)
PC=0x00000000; MSR=0x0000D030; DAR=0x00000000; DSISR=0x00000000; LR=0x00000000; R1=0x00000000; XCP=0x00000000 (Unknown)

Kernel version:
Darwin Kernel Version 8.11.0: Wed Oct 10 18:26:00 PDT 2007; root:xnu-792.24.17~1/RELEASE_PPC
*******

Wed Oct 22 22:56:04 2008
panic(cpu 1 caller 0x000A4EC8): simple lock (0x003DA020) deadlock detection, pc=0x00033564

Latest stack backtrace for cpu 1:
Backtrace:

backtrace terminated - frame outside of RAM: v=0x37892A50, p=00007DAA

Proceeding back via exception chain:
Exception state (sv=0x5FD47780)
PC=0x000AF53C; MSR=0x00009000; DAR=0xF0182EC4; DSISR=0x42000000; LR=0x000340A8; R1=0x473A3E30; XCP=0x00000024 (0x900 - Decrementer)
Backtrace:

backtrace terminated - frame outside of RAM: v=0x473A3E30, p=00105E87

Exception state (sv=0x5F4E2280)
PC=0x00000000; MSR=0x0000D030; DAR=0x00000000; DSISR=0x00000000; LR=0x00000000; R1=0x00000000; XCP=0x00000000 (Unknown)

Kernel version:
Darwin Kernel Version 8.11.0: Wed Oct 10 18:26:00 PDT 2007; root:xnu-792.24.17~1/RELEASE_PPC
*******

Any ideas? Does this log look like a bad RAM module, simply bad RAM or worse?

rif raf what's the spec of your G5? Mine is a dual G5 2.3Ghz.

I seem to have managed to fix my G5, the steps I took will invalidate any existing warranty, so I don't recommend it to anyone who still has Applecare cover. Call Applecare if you had cover, they may help you, in my case I they said would have to pay.

I also don't recommend this to anyone who is not technically competent at working inside a computer. You run the risk of destroying your computer, or harming yourself.
My G5 was out of warranty, and I can't afford the repair costs at the moment. Take it to an Authorized Apple Service center if you can afford too. As mentioned previously I have a manual that lists the take apart steps, and the Apple Diagnostic CD - google is your friend.


This is just my experience…

I removed the processors, logic board and power supply unit (PSU) I cleaned them carefully with a can of compressed air and a hoover. I inspected the solder joints, they looked in good condition. The PSU has burned resistors (photos linked earlier in this thread), but otherwise it worked ok.

I also removed the PCI divider from the logic board to make it easier to clean & handle.

On the processors there are 4 hex screws that clamp the heat sink onto the chips, I loosed these slightly and carefully redid them. They look like they may benefit from a good electrical connection. I left the processors on their heat sinks, and planned to remove them if this first repair attempt failed.

On the back of the logic board I have several heat sinks - I think 2 are very well stuck (one is small, and the other has a large 'cooling pipe' coming from it) I left these 2 on the board and removed a third one. It was clipped in place with white plastic posts and springs, and the heat sink was connected with thermal paste.
I believe it is the memory controller. It seems that earlier models don't have this chip & heat sink, so perhaps it is actually part of the graphics or PCI system?

I cleaned the chip and sink, and replaced the thermal paste. I cleaned the remaining parts in the case & removed and reconnected any other items I could get at, including the bluetooth aerial, and the ambient board (a tiny board on the logic board that locates at the front of the G5 case).

I stuck it all back together and started it up It ran with 2 processors 🙂 The next restart only had one processor show up, so I reset the PMU and NVRAM. Then I ran the diagnostic CD. Since then it has run with 2 processors, and has not gone into 'fans on full lockup mode' while sleeping.

I haven't had any other issues for a two days now and would say that one of the above steps has resolved this problem, not sure which one though.

I'll report back if this changes at all.

Please be careful - I accept no consequences if you break your mac!

Hope this helps,
Drew

Hey Drew,

Mine is a dual 2.0. I'm not the least bit squeamish about opening mine up, actually studying the applecare tech guide - which it seems every mac owner should be doing if current performance/build quality is any indication. I never had applecare - so if I can stomach ever buying a mac again, lesson learned.

I can't afford a new one either at the moment, and I'm looking at an extension on a deadline, so yea I'm in a bit of a bind like you. I did take it to an authorized center, and they gave me a load of crap about it being a failed hard drive. Mind you they obviously didn't give it the cleaning I ended up giving it. After repairing that drive with DiskWarrior and using an entirely new one - same problems persisted. I did also call customer support, however according to them "they weren't aware of this issue happening on a wide scale". Funny since I've seen forums here and on macupdate, detailing various user experiences , on these exact models, with exact issues nearly down to the kernel panics (Tenoch's almost mirrors the consist on-screen panic I've seen to excuse the put - a "T").

The one thing I failed to mention was after the initial cleaning, it worked fine for a few days - then it was back to the same ole' same ole'. So hopefully you'll have better luck than I. The other issue was I couldn't quite figure out was how to open the psu casing. So I just blew it out end to end and checked it with a flashlight as best possible. Quite a bit came out, but there could be more dust caked up around individual wires/components. Mine does rest on a hardwood floor, so despite having a blueair air filter in the same room - its possible this could have led to just enough accumulation to make the issue reemerge. Not sure how likely enough could accumulate over a few days of light use.

What I haven't done is taken out the logic board or used a vacuum (I think this is where my Dyson will come in handy). Also, I hadn't noticed a third heatsink, but I could have just been referencing my take-apart guide too closely to notice - or it may be a slight variation between dual 2.0s and dual 2.3s.

Since I'll have everything out I might as well give the processors another cleaning and reseating. Thanks for the added input, hopefully your "spring cleaning" won't lead you back to square one as I've been. I'll share results when I finish hopefully tomorrow.

Overall, this is just really disappointing. My mac is not even 4 years old yet, and while I'll eventually be moving to the Intel version since certain software is phasing out for PPCs (After Effects & Premier Pro) - this isn't too encouraging for what I can expect from a newer purchase 3-4 years down the line.

rif raf,

it looks like I got 5 days of life out of my G5 after the spring cleaning!

I'm sad to say the a few hours ago it had gone into 'overdrive fans mode' while asleep. The next startup was back to running on 1 processor. I'm back to my borked mac.

I think sleep MUST be avoided at all costs with these G5's because there are too many cases of the 'jet fans' happening when asleep. I suspect the processor or logic board fails/ overheats when freezing while sleeping.

I feel kinda stupid now for letting it sleep, but I was leaving the room for 20 mins, force of habit I think.

I ran the diagnosis CD and it gave me the serial no for the active PSU. So I removed both and then reseated the heatsink on the one that was missing. It made no difference. I may try doing the other one, but this has happened during another deadline, so it will have to wait, again.

I think it's almost time to give up and take it for the Geniuses to diagnose.

This issue is somewhat ridiculous there are 4 people on this thread reporting a 'lost processor' …
http://discussions.apple.com/thread.jspa?messageID=7150914
In addition to the 5 people on this current thread,
and another person on this thread (with 2 dead G5's?)
http://discussions.apple.com/post!reply.jspa?messageID=8367337

There are also countless reports of the 'fans on full & locked up in sleep' issue. Is it only me that thinks these are related?

Does Apple monitor these issues or are we all wasting our time?

I had the exact same experience as Whoopy the original poster with my G5 dual 2Ghz...

I got the same "System failure: cpu=1; code =00000001 (corrupt stack) error message and all...

I have a friend working in a mac repair shop here in Denmark who had it in for service, and he found that I needed to have exchanged both processors and logicboard. I think this issue is more or less the same on all G5's from that period.

Anyway, I decided to not have it fixed as the cost of that was more or less equal to a new mac pro in standard config. So now I have a nice paperweight in aluminium if Apple decides to not do anything about it...

I did not get applecare when I bought it in 2004, and I did not regret not getting it from what I can read on theese forums...


Regards

Morten

Same problem here with a dual 2.5

Tried everything tests show nothing wrong with the computer. Freezes no matter what I do. Sometimes won't start up. When it does start it will freeze in a few minutes. The longest it has gone without freezing is an hour.

I have a 1.8 dual G5. I opened my case and reseated the RAM. It worked for a day and back to the maddess. I'm in the process of figuring out what I want to do with this issue.

So that makes 13 dead G5's showing similar symptoms.
What will it take to become a known issue?

Has anyone still got Applecare, I imgine we are past the 3 year limit for most of these machines?

Somewhat depressing - spending £2000 isn't enough to get a Mac that will run for more than 3 years.
Note to self - stop recommending Apple.

This is my second mac to die like this after 3 years of use. Both times I bought top of the line dual processor power macs. Last was a dual 800 g4. It is kind of crazy to have a top of the line multi thousand dollar macs die in 3 years.

Well I opened my tower up again and took a look by the processors. I found a burnt brown spot and some green liquid in there. It appears my liquid coolant leaked. You guys may want to check that area out if you have a liquid cooled g5. I did some research and found a bunch of other people have had coolant leaks on g5's in the past year.

http://www.xlr8yourmac.com/systems/G5coolantleaks.html#updates

I've started to experience the same problems with my PPC Dual 2.0GHz G5. Woke up one morning to hear the afterburners kicking in, now ever since it cycles between starting fine, but running slow, freezing after start up, or powering on but not booting up. I have run an anti-virus program on the hard drive numerous times, ran the Apple hardware test, both came back with no errors at all. Interior of case had only slight surface dust, no big dust bunnies or chunks.

Tonight I plan to re-load the OS and see if the problem persists. From what I've read I have a feeling it will. From what I gather it looks like it will be time to take it in to be looked at and then decide whether to fix or buy new.

Hasn't even lasted me 4 years yet, computer is a June '04 build bought in June of '05.