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

I have gone thru all the same symptoms too. I lucked out with a "one time only service comp", so the genius bar did everything they could to revive G5 dual 2.5 (liquid cooled not leaking). Power supply, ram, logic board, then a processor core failed, and fixing that, the video card failed, all a continuing succession of major nightmares so they had to give up. I wonder if anyone knew long ago that this generation of computers was destined for misfortune. Alas...

I have the same symptoms as many of you. The kernel panic/system freeze followed by the inability to restart past the gray Apple screen. I took it to the Apple Store and tried to boot it from their drive and no luck. It won't boot in safe mode, from disc or a bootable hard drive. It can be started up as an external hard drive, but that's it. The genius at the Apple Store said he thought it was the logic board and it'd be $700+ to repair and they wouldn't know for sure if that would fix until after the fact, but I'd still have to pay for the board.

Next, I took it to an AARC who just now informed me they think it's the power supply. I hesitated, because they're going to charge me in the neighborhood of $475 for parts and labor to replace it, but I gave them the go ahead. That was before I found this thread and now I'm thinking I should call them back and cut my losses, but I'm also curious to see if the power supply is really the problem. Unfortunately, they won't guarantee that it will fix it, only that they're pretty confident that it's the problem.

If I don't back out and actually have them fix it, I will post here whether or not it worked.

I feel honored that I am also a member of this growing number of loyal apple owners to have his beautiful G5 dual 2.5GHz that has worked without issue and flawlessly for 5 years suddenly in the last week die. I could list all the symptoms, but they have all been listed on here.

Worked flawlessly until two weeks ago when kernel panics started every 5-10 minutes. New video card from apple for $450 allowed me to get all important audio (I am a mastering engineer) off the machine, but after 4 hours of turning on the repaired computer, it began again with the kernel panics and crashing. Now it won't boot and just sits on the grey screen with the spinning circle. I am off to apple tomorrow afternoon to have a chat with them about the issues, but I fear that I am mourning a dead computer that was taken care of for its entire lifespan.

On a side note, I am now working on my 10 year old G4 which still runs flawlessly. I will update the processor in that machine and use it instead to do the audio. I have lost confidence in apple over this. I don't like spending $500 to fix a machine to have it ocme back in worse shape than before.

We do not walk alone, we have all done what we can, and now we know that there is a problem with the G5's that gives them a limited lifespan due to the logic board design. Thanks apple. It ***** our $3000 machines are doorstops now, and it is eyeopening that my 10 year old G4 is a better computer than the newer G5's that are all dying.

I just picked up my G5 after having the power supply replaced. $475 parts and labor and so far so good. It's only been a short time and I obviously won't really know for a week or more, but it is working and I'll keep you posted.

Last week (Monday morning), one of our two G5's that we use to run our small prepress company came down with these symptoms. Tried every troubleshooting step I could find, short of taking it in for repairs(owners are not willing to pay for it). So I have been having to bring my own computer(pc) in to work to get things done. Just yesterday, the other G5 started doing the same thing.

I find it odd that both machines start freezing and not booting up within roughly a week of each other. Strangely, the one it happened to first is newer by about a year. Both machines have a slightly different configuration. One is a 1.8GHz Dual with 512K of RAM. The other is a 2GHz Dual with 2GB of RAM. Both running Panther, both PowerMac.

I haven't tried reinstalling the OS, but I doubt I would be able to since the computers rarely boot, and when they do, they freeze randomly. My gut feeling is that it is a hardware issue, maybe overheating. I have noticed that they will often get all the way to initializing the Finder if they are off for about half an hour. I've read through most of the postings and some people said there was some visible heat damage on either the processors, power supply, or logic board. Not sure if I would find this on ours. We'll be taking them in to the Apple store today for free diagnostics, but I doubt the news will be good. Needless to say, we are in a bind with deadlines approaching.

I too have a dead G5. Never had any problem and now this! With so many having this issue, couldn't it be an update flaw of some sort? That was my first thought after it crashed the first time. It continued to crash with the time between start-up and crash getting shorter and shorter until it no longer boots at all! occasionally I can get the start-up tone then nothing. Surely Apple is aware of this. I really do believe it is a result of the last update and now I cant even boot from disk to load the OS and wipe the hard drive.
Thank Jobs I still have my G4!

I have been having my G5 Dl 2.0 freeze up for the past month.
I have tried numerous things, PRAM reset, in Disk Utility I have repaired and verified permissions.
Now after WEEKs of sufferring I finally just said to heck with it and I went into "Library" and also into the user "Library" and I TRASHED ALL the "Prefs" inside the Preferences Folder.
My main problem was that when I needed to burn my DVD Project in iDVD, the Tower would run fine, sometimes for 5 minutes then it would go into " JET Engine" mode with fans blowing at full speed....sometims it would run fine for an hour..THEN it would Freeze up....NOW after deleting EVERYTHING...every Folder in BOTH my Prefs Folders...it is running fine and my 90 min...DVD is almost done....I will keep my fingers crossed and hope it all turns out fine.
Now I just have to see what has been affected "negatively"..by my actions.
Right now I see that I will have to redo my DOCK, I w have to bring back all my app icons, i.e. FCP,PS,LiveType,etc

I also have a dead dual 2 ppc mac. 2 weeks ago it started misbehaving. Now it's gone. It's shameful the way Apple has no respect for their customers hard earned money. That machine is my mill stone. My work is suffering because I trusted Apples claim to producing decent machines. I'd like to believe that they are a company who takes responsibility for their actions when they find this many untis going south. I'll be taking a trip to the genius bar for info gathering purposes. They said they will do a diagnostic for free... I know for a fact that the one genius I talked to has one of these and HIS crapped the bed too. I've been reading post after post on forum after forum and they all sound the same..."***? Who is this company and what did they do with the Apple I grew to know and love?"
Eventually my hope is that the machine is fixed by an independent outfit who cares about their reputation and knows how to put my baby back together so that this won't happen again and Apple picks up the bill.
I've been with Apple since the apple IIc. I've owned a quadra, an iMac rev.b, a graphite iMac and all have performed beatifully.
in fact the one that is still here still works and the ones that left here, left working. What has happened here is unacceptable. I've been reduced to using an HP pavilion I got from a swap shop for $150.00 to write this. It works flawlessly. In the background I can hear Justin Long touting the benefits of owning a Mac on TV.
Meanwhile, the $3800.00 PPC Mac on my desktop is a tombstone.

My PowerMac G5 Dual 2.3 GHz has also a defect logicboard after 4.5 years. Most likely it is the Northbridge Chip (U3) which has to be reflowed to get it working without changing the logicboard. The first reflow doesnt work and the second one will be the last one in any case. Thinking about buying a new computer it is not an easy decision to buy another Apple system (e.g. Mac Pro).

Why on earth is the replacement of the logicboard so expensive? I would expect from Apple a low cost solution for the replacement of the logicboard as a minimum to satisfy there loyal customers.

Nice (sic!)
I was just about to buy G5 in good price. I was almost sure. After reading this thread, I am shocked how badly Apple treat users! I was about to start my adventure with Mac (well ages ago i used one with e603 proc).But i am disgusted!
Especially knowing that most of users of G5 power macs are professionals, designers,etc. - what a blow. Nice one APPLE!
I am out.

Back again. I can report a successful reflow of the Nordbridge in my G5. I've found a company which are able to reflow the northbridge of the G5. I expect this is the reason for the majority of dead G5 systems. In my case the first reflow was not strong enough but the second one (it was a heavy one 🙂 was successful. It is not without risk for but its obviously worth a try.

Regards
Michael

Hello, can you explain exactly what the reflow process is? Thank you

Hello John,

the explaining is documented here:

<http://www-01.ibm.com/chips/techlib/techlib.nsf/techdocs/59BEA03A4FA9E41787256F D600710800/$file/BGA%20Solution%20for%20G5.pdf>

Temperature variations are the reason for the Northbridge problems we have with our G5 machines. The connection to the logicboard is broken so you have to reflow this chip. Information about reflow and BGA can be found here:

<http://en.wikipedia.org/wiki/Reflow_soldering>
<http://en.wikipedia.org/wiki/Ball gridarray>

A reflow worked for my G5. According to my experience local Apple dealers were not able to detect the reason. One dealer told me the logicboard is ok according to his hardware test program. The next dealer offered me to replace the logicboard and/or the CPUs.

The company which made the reflow can be found here (Germany): <www.golytronic.de>. They have much experience in repairing Apple systems, especially on chip level. According to my experience they are very trustworthy. Hope the international shipping costs are not to high.

Good luck
Michael

OK, count me officially in too. What does that make the numbers in just this thread alone of the many threads on the internet?

My dual G5 2.0 ghz; started dying this summer during a hot spell. Apple replaced the PSU under an extended recall program they had (by coincidence it was days before the program expired).

I was very happy that they'd fixed the problem for me and was quite happy to share that with essentially all the faculty and students at the Harbourside Institute, a Mac-based engineering and production school at which I teach.

But yesterday it went belly up on me. Restarts are fairly useless; most of the time it won't pass the grey/dark grey apple startup screen and the gear underneath either does not start, or starts spinning normally until it slowly becomes overprinted with a "hash" of pixels, at which point it sticks. Unplugging it for a couple of minutes and replugging it can get me a viable boot about one time in three; on those occasions that it will boot, it crashes within minutes of desktop appearing - the mouse remains movable but the screen is unresponsive to clicks and any processes displayed on the screen become frozen.

I have cleaned it thoroughly with compressed air. I have checked the mobo battery (replaced a few months back); I have booted into Open Firmware and reset parameters, and I have inspected the insides for visibly bulged caps (not found yet, I will be disassembling it more fully shortly).

Tech support disclaimed knowledge of this issue today. I asked for a supervisor, and when I spoke to him about the issue (which he was somewhat evasive about acknowledging) I asked him simply for a guide to disassemble the G5, since - as I informed him - I'd rather just +fix the problem myself+ with the aid of a tech friend and get back up and running than turn this into a cause. He absorbed the links I read to him with little comment and told me he was sorry but there was nothing he could do for me and told me there was nobody higher in the food chain I could appeal to - he was the "last court of appeal" as it were.

Having read and digested hundreds of pages of information today on this issue (I found disassembly documents within minutes of searching the web after my call), it seems the following summation is in order:

The G5 is prone to several issues. One critical and known flaw is presently presumed to be related to thermal expansion of the Northbridge chip and associated systems, leading to failure of the BGA that connects it to the system board.

This, incidentally, is explicitly referred to at golytronics.de (who include amongst their specialities repairing G5s) as a *production defect*.

Other issues that may or may not affect the G5 include the widely publicized "liquid cooling system leak" and may possibly include the inclusion of defective capacitors (a widely publicized issue found in Wikipedia.org under the name of "capacitor plague").

So as far as I'm concerned, this is a classic "lemon". A time bomb waiting to go off - negligence at the most charitable interpretation, "planned obsolescence" at worst.

It is reasonable to assume that Apple is fully aware of this issue. It is widely publicized, and it affects a great number of purchasers of the G5. There is thorough documentation in the posts above that demonstrates that Apple was aware of technical issues surrounding the BGA and thermal expansion. Apple, however, does not consistently acknowledge that it knows about this issue, and by implication disavows responsibility for it.

I have been a customer of Apple's since 1994. Lest anybody tell me that it's unreasonable to expect a computer to last more than five years, let me set you straight. My first Mac was an LC475, which is still running over at my cousin's house. My second was a 7600, my third was a beige G3, then a more powerful beige G3, then a blue and white G4. After that it was an iBook, then an eMac G4. Finally I got my G5 - and I was happy. The 475 is still in operation. I still have the two G3s and both ran when I checked them earlier this year. The iBook is sitting in my cupboard as a backup laptop, still functional except for a broken CD drive.

So - ironically - my expectations of how long a computer should continue to function were actually set by Apple itself.

Each of those computers was, in its turn, new technology. The principles involved in the faulty construction of the G5 are not issues of new technology. *Solder joins and the strains placed upon them by thermal expansion are not new technologies*.

My G5 is toast; the cost of repairing it far, far exceeds the value of the computer, the repair is not guaranteed to work, and worse - the logic board will be replaced by a logic board that must be presumed to potentially have the same issue (I've begun taking note of how many G5s are available on my local Craigslist for parts because of *logic board failure*; I am surprised that I never noticed their numbers before).

I am severely displeased at this moment and I am considering my options. *Apple - are you listening? There's a loyal, 15-year die-hard user here who really hopes you are.*

Hello Michael,

Thank you very much for all of the information you have provided. I have read the material in your links and even contacted Golytronic, but unfortunately, I do not read or speak German, so I've had some difficulty determining if I will be able to ship my computer to Germany for repair in a cost effective manner. As a result, I have a couple of questions for you.

1. What was the total cost of the reflow for your computer?
2. As it is overly expensive to ship the entire computer, do you know if I would be able to just ship the CPU Assembly?

Thanks in advance for any information or advice you may be able to provide.

Michael.