My Powermac G5 freezes after a few hours and fails to start up regularly!!

[boziboy]

Hello Mac world,

Specs:
Dual 2.0 powermac G5
1.5 gigs RAM (1 gig is Kinsington)


I am desperately seeking your help because the Apple store has not been any help to me.
I have a Powermac G5 (i think late 2004) that worked like a stallion for 4 years. Now it will freeze after about 3 hours of use, and when I force shut down it will not start up, or it will sometimes start the next day and sometimes not for 3 days.
When I push the power button I see no LED light, no chime or fans...nothing!I've unplugged everything, waited a few hours, then plugged everything back in and nothing. I've reset the PMU via the button that is near the RAM modules and that did not do anything. I've also taken out the third party RAM that I had in there and it still performs the same.
I've replaced the clock battery and performed a completely clean install of Leopard.
I've managed to get a hold of Apple's ASD (Apple Service Diagnostic) CD and that doesn't show any hardware or OS specific problems, nor does any other diagnostic CD. I haven't run stress tests but i'm sure that Apple has already done that.
Basically, Apple told me that it could be the logic board, processors or power supply. Based on the problems that G5's have had with their power supply's, and the fact that my serial is relatively close to their cut-off numbers tells me that I might have a faulty power supply. I've also heard about third party RAM conflicting with apple updates, in which case I also have third party RAM installed. I want to salvage this computer and I would be forever grateful for anyone's help!

Thanks for reading the wall of text,

Jason

 

[cult]

Jason,

You might also want to rule out a leak in the liquid cooling system. Apparently many G5s are prone to this issue and it causes some of the same symptoms you are experiencing. Signs are corrosion on the bottom of the case and antifreeze looking material seeping out. This issue is the reason I decided to buy a used G4 dual over a G5, even though the G4s are significantly slower. I got one for $200 today and so far it runs Leopard beautifully.

 

[boziboy]

Thank you for your help! I forgot to mention that my machine is the model just before the liquid cooled macs came out. I just saw a dual G4 going for $800, so you got a great deal.
Anyways, the more and more I've been reading it seems like my problem is geared towards my power supply. I say this only because when I push the power button I do not see an LED light and the computer is dead silent. After a day the computer might turn on, and if it does it will work for a couple of hours and then freeze. In which case, I need to force power down and wait another day.

Jason,

You might also want to rule out a leak in the liquid cooling system. Apparently many G5s are prone to this issue and it causes some of the same symptoms you are experiencing. Signs are corrosion on the bottom of the case and antifreeze looking material seeping out. This issue is the reason I decided to buy a used G4 dual over a G5, even though the G4s are significantly slower. I got one for $200 today and so far it runs Leopard beautifully.

 

[OrangeSVTguy]

Thank you for your help! I forgot to mention that my machine is the model just before the liquid cooled macs came out. I just saw a dual G4 going for $800, so you got a great deal.
Anyways, the more and more I've been reading it seems like my problem is geared towards my power supply. I say this only because when I push the power button I do not see an LED light and the computer is dead silent. After a day the computer might turn on, and if it does it will work for a couple of hours and then freeze. In which case, I need to force power down and wait another day.

Check Apple's website to see if you fall under their warranty program for the failing systems. http://www.apple.com/support/powermac/powersupply/repairextension/

Have you tried cleaning out your system? Take all the fan out and clean all the dust off them either by blowing on it or using compressed air. Using a toothbrush works too in the small crevices.

 

[kinnyboy]

I also have had a similar problem and have traced it to one of the processors going down intermittently. Apparently its surprisingly common. Check this thread out for help etc

http://discussions.apple.com/thread.jspa?threadID=1672650&tstart=0

 

[boziboy]

Check Apple's website to see if you fall under their warranty program for the failing systems. http://www.apple.com/support/powermac/powersupply/repairextension/

Have you tried cleaning out your system? Take all the fan out and clean all the dust off them either by blowing on it or using compressed air. Using a toothbrush works too in the small crevices.

Hello OrangeSVTguy!

My G5 ran out of apple care about a year ago and my serial number is not within the range of the power supply recall program. My serial number starts with G84XX and the starting serial number of the repair program is G8538. I've used compressed air and have gotten as much of the dust out as i can. It's not dusty at all. Thank you for your help!

 

[boziboy]

I also have had a similar problem and have traced it to one of the processors going down intermittently. Apparently its surprisingly common. Check this thread out for help etc

http://discussions.apple.com/thread.jspa?threadID=1672650&tstart=0

Hello kinnyboy,

I only experience some of those problems that are listed in that discussion. My computer either boots up and runs perfectly for about 3 hours and then freezes. My fans sound totally fine until it freezes, in which case it will progressively rev up until it sounds like a jet engine. When I force shut down it will not boot back up until a couple of days later. Thank you very much for the help!

 

[boziboy]

Just to update... I replaced the power supply and it did not solve the irregular power up.

 

[smarkie]

I finally gave up on my 4-year-old PowerMac G5 2.5GHz (late 2004 model), which, like your G5, was a workhorse (always on, except when I took it down for upgrades or updates--I had maxed out the RAM and had nearly 1TB of disk inside), for 4 full years until it started refusing to start. The trouble seemed to begin with a routine upgrade to Safari, which required a restart. I left the room during the restart, and came back to roaring fans and a grey screen! To make a long, LONG story short, after this it wouldn't restart at all, and would only cold start 1 time out of 5 (unplugging it and waiting a few hours sometimes worked and sometimes didn't). Zapping the SMU, PRAM, starting from another disk or the CD, doing a clean OS install, etc. would SEEM to help, but never permanently. It would always eventually hang up at some point after the boot chime, usually with either a grey screen, or a screen with the Apple and a frozen spinner. In addition, there would be a red LED on, deep in the machine behind the processors. Also, if you let it sit this way, eventually the fans would come on and rev up until it sounded like a jet taking off...

Apple finally diagnosed (after 2 different visits over the course of a week--and this is a HEAVY machine to be hauling around a shopping mall during the holiday shopping season) a bad logic board and possibly a bad processor. And the replacement board and processors for this particular machine would run me something like $2000, no matter where I get them (the logic board for this Mac is MUCH more expensive than the board for some of the other G5s), WAY more than the machine is worth! Besides, this is a liquid-cooled machine, and I just don't want to mess with that (though there is, apparently, no leakage, and the power supply is fine). So, I've scavenged the working parts to put in my Mac Pro (disk drives, optical drive), and maybe someone will be interested in taking the rest for parts...although I've yet to find anyone locally (Northeastern US) who wants it for that. It'd be a shame for such a pretty case to go to a landfill, though...

I'm shocked at how many reports I've read recently about PowerMac G5s that die after 3-4 years, long after they're out of any sort of warranty, and after working perfectly for a long time... I'm wondering if the fact that the processors on these run so HOT has anything to do with it. BTW, boziboy, my serial # is also in the G84xxx range...not in the groups covered by the power supply recall.

 

[mr.scappy]

My G5 died after Leopard install

Just thought I'd add my two cents here. My four-year-old G5 2.7 died two weeks ago after a Leopard install. It had been running on 10.4.11, and I'd had no problems with it at all over its lifetime.

After installing Leopard, I restarted the machine. Five minutes later, the fans ramped up speed, the screen froze and I had to hold the power button to power down the machine. I tried the same thing that many other posters here and elsewhere have tried: removing 3rd-party RAM, zapping PRAM, unplugging the machine for hours, resetting the PMU and so on. On power up, I'd get a grey screen, or nothing at all, though occasionally the desktop would come up briefly before freezing. At one point I got the machine running long enough to reinstall Tiger, but when I did the usual upgrades to get back to 10.4.11, the machine froze again.

I took it to Apple and was told -- yes, you guessed it -- bad processor ($800) or logic board ($1300).

Why do so many G5 users have logic board and/or processor failures after four years, and often after upgrading to Leopard? I'm beginning to smell a class-action lawsuit.

 

[Sweetfeld28]

I am currently at work, working on my Dell PowerEdge 2900, because my Dual Core G5 2.5 GHz. has a faulty Logicboard. I to don't expect to find a good deal on any replacement parts for it, so it just sits in my office acting like an over sized paper weight.

It has had its AppleCare expunged a couple of years ago, there will be no Apple help on this issue. I called a local Authorized Apple Retailer, and they told me it would be $900 for a new board, and another $100 for Diagnostics fees.

The thing i can't believe is that of all the numerous reports of dead mother/logic boards on the net, i would think Apple would have a replacement program in place. But, I digress.

 

[boziboy]

I know it has been a while, but I've been staring at my dead G5 for almost a year now and I'm wondering if anyone has new information regarding my problems. So far I've also replaced my power supply, and now it won't start up at all. I'm considering putting back the original power supply but only after I buy a new logic board.



My questions:

1. Is replacing the logic board the best answer (considering my problems)? Or should I consider the processors too?.

I thank everyone who has helped me so far. I love this computer and it seriously rocked hard when it was working.

 

[gugucom]

I started my Apple desktop experience with a 1,8 GHz DP 2004 which had exactly the problem described. One of the CPUs was defect. I was lucky that up to 1,8 GHz you can easily analyse that fault by removing CPUs. Because Apple build machines with the same logic board and only one CPU socket they retain the capability to run with only one CPU.

If you keep one CPU in slot A and remove the other one you find out if it is defect. Then swap the other CPU into slot A (the upper) and you will have run the total test. It is very simple because the CPU sits on a daughter board and you do not have to mess with thermal paste. The probability to do damage is minimal. Unfortunately the diagnosis program on the CD does not catch those faults.

In my case I ended up buying a set of used 2,0 GHz CPUs for 150$ off Ebay Germany. I had a speed upgrade and they ran fine. I have since upgraded my machine twice (first to 2005 2,3 GHz dual core then to 2006 Mac Pro). I keep seeing an awefull lot of PM G5s with that CPU burn out.

 

[UltraNEO*]

I keep seeing an awefull lot of PM G5s with that CPU burn out.

One of my friend had purchased a PM Dual G5 when they were still current. I think it's a 2.5Ghz version thought I'm not completely sure, it work fine for about six months before it started to crash randomly. On my prompting, he returned the machine to his supplier, after a couple of days one of their engineers called and suggested the logicboard and processors needs to be replace!!!

I, myself was a little shocked cause all the time I've owned Macs they've been really reliable... Now I'm a member of this community I discover those so-called supercomputers we're kinda a shoddy. I wonder, is it caused by Apple pushing it's hardware a little too much? As CPU's don't tend to fail this often or should we put the blame on IBM & Motorola since they manufactured the bulk of them.

 

[giffut]

Leopard ...

... puts more thermal stress on older machines CPU/logicboard, as it is more demanding and simply requires more power to run, especially the older the hardware becomes. I could very easily spot myself this when I installed 10.5 on an Powerbook Titanium 1Ghz with 1GB RAM, who was fine with 10.4, but got beaten heavily while running Leopard.

Now, the additional thermal stress can bring illfated joints, capacitors, etc. to its knees faster; in a way, Leopard did just speed up the already present failure, hiding under the hood.

 

[gugucom]

I would rather go along with the theory that these machines with the PPC970FX were designed with critical cooling requirements. Apple took the rather desperate step to use liquide cooling on the higher steppings. I dissasembled one of the damaged CPUs from the heat sink and I wasn't impressed with the way the CPU was secured between the daugther board and the heat sink. There were several bolts through the PCB for guidance which required considerable force to overcome the friction and the PCB was bending under the connecting force of the dinky screws that build up the force. If someone was a bit careless with assembly of this design and with the application of thermal grease the heat transfer into the sink could be considerably reduced.

The G5 heat sinks also had no thermal sensors as the Mac Pro heat sink does. It required a akward thermal calibration which could go wrong I guess if you made mistakes in the program. Apple technicians are not allways as excellent as you would want them to be. I just had the opportunity to replace two Xeon CPUs in my Mac Pro which had been assembled by an Apple AASP. I almost ruined my logic board because they had applied approximately 3 times the amount of thermal grease that you need. It got squeezed all over the clamp mechanism and it took me half an hour to remove the excess prior to removing the CPUs. Still I almost got thermal grease into the socket pins when the clamp frame fell back after the CPU removal. There was even grease on the underside of the clamp. I was lucky it got not stuck between the pins of the socket.

 

[California]

I think there was some software issue, too.

General recommend on G5s... set power settings to highest not automatic.

Mine run better on Leopard than Tiger.

Use original discs for initial hard drive install, then upgrade to Leopard with discs; this seems to fix the software issues.

Also, failing hard drives are notoriously difficult to diagnose on G5s for some reason. Hard drives are so cheap now that no one has an excuse not to get new hds every two years.

The lower end G5s are completely different machines to me than these

2.5ghz dual processor
2.7ghz dual processor

2.0ghz dual core
2.3ghz dual core
2.5ghz quad core

These are the only G5's I'd touch.

Apple is very good with fixing leaky G5s, so its really not an issue for me.

Put enough ram in them, new hard drives, properly installed software, dust free, they are a BARGAIN.

 

[California]

I would rather go along with the theory that these machines with the PPC970FX were designed with critical cooling requirements. Apple took the rather desperate step to use liquide cooling on the higher steppings. I dissasembled one of the damaged CPUs from the heat sink and I wasn't impressed with the way the CPU was secured between the daugther board and the heat sink. There were several bolts through the PCB for guidance which required considerable force to overcome the friction and the PCB was bending under the connecting force of the dinky screws that build up the force. If someone was a bit careless with assembly of this design and with the application of thermal grease the heat transfer into the sink could be considerably reduced.

The G5 heat sinks also had no thermal sensors as the Mac Pro heat sink does. It required a akward thermal calibration which could go wrong I guess if you made mistakes in the program. Apple technicians are not allways as excellent as you would want them to be. I just had the opportunity to replace two Xeon CPUs in my Mac Pro which had been assembled by an Apple AASP. I almost ruined my logic board because they had applied approximately 3 times the amount of thermal grease that you need. It got squeezed all over the clamp mechanism and it took me half an hour to remove the excess prior to removing the CPUs. Still I almost got thermal grease into the socket pins when the clamp frame fell back after the CPU removal. There was even grease on the underside of the clamp. I was lucky it got not stuck between the pins of the socket.

This could be the strange failure rate on some G5 dual processors: human error in at time of manufacture. I believe the dual cores G5s are put together slightly differently?

 

[gugucom]

oops, forgot the recommendation. Buy yourself a pair of proper 2,0 GHz CPUs with identical Apple numbers but go by those on the PCB. They are sold at reasonable prices on Ebay by private sellers who had logic board failures. With two replacements chances are good you will have two or three good ones. Experiment to find those that are good.

 

[boziboy]

Apple finally diagnosed (after 2 different visits over the course of a week--and this is a HEAVY machine to be hauling around a shopping mall during the holiday shopping season) a bad logic board and possibly a bad processor. ....I'm shocked at how many reports I've read recently about PowerMac G5s that die after 3-4 years, long after they're out of any sort of warranty, and after working perfectly for a long time... I'm wondering if the fact that the processors on these run so HOT has anything to do with it. BTW, boziboy, my serial # is also in the G84xxx range...not in the groups covered by the power supply recall.

I'm done carrying my G5 through the shopping center. It's too much of a hassle and Apple didn't much for me besides say "we were able to replicate the problem but we can't tell which part u have to replace". I too am shocked at how many people are reporting failures with this model and especially around 2004-05. I've found used logic boards for the 820-1592-A model for around $400 and dual 2.0 processors for about $200. So, i think i'm going to start with the logic board because that is the most involved. I'm just waiting to see if some hardcore pro in this forum can read my diagnosis and say "oh yeah inconsistent power ups? system freezes after 2 hours or processor intensive tasks? Yeah, that's a faulty (insert part)"

Edit: I sent this after the hardcore pro's responded to this thread

 

[boziboy]

oops, forgot the recommendation. Buy yourself a pair of proper 2,0 GHz CPUs with identical Apple numbers but go by those on the PCB. They are sold at reasonable prices on Ebay by private sellers who had logic board failures. With two replacements chances are good you will have two or three good ones. Experiment to find those that are good.

I was thinking of purchasing and replacing the the logic board first, Just because I can't pinpoint where the failure is. But since I've read your descriptions I'm going to try buying a matched pair of Dual 2.0 CPU's. Also, I am unfamiliar with the term PCB. Right now the computer won't start up at all after I replaced the power supply. I'm going to replace the original power supplu and see if the computer at least turns on.

Sheesh, this is going to take a while. I'll keep everyone updated. Thanks again to those that have been helping me, this is why I love these forums!

 

[gugucom]

PCB is used for printed circuit board. I recommend using the part number on the label of the daugther board. There is another one on the heat sink, which is different.

 

[giffut]

Just ...

... buy a working used one similar to yours off from eBay. It may run hills cheaper than a logicboard repair itself, even second hand.

Regarding the CPUs: Just buy a broken G5 Dual 2Ghz. Very likely the motherboard is the culprit, and even if not, you have at least two working CPUs for sure you can swap to check if it´s the CPU anyway - but Apples Service Diagnostics would have showed you this failure, so I am quite in doubts that any CPU is to blame here.

Set yourself a severe money limit on this one and do think about dumping it alltogether and make the jump to an Intel Mac.

 

[Dr.Pants]

I would say that it was the logic board - I assume over the course of the past year you have re-seated your processors, so they shouldn't be the problem; if a part in the CPU was fried, I would imagine that it wouldn't turn on at all.

That's just me - but probably best to replace both at anyrate. EDIT- Or, like Giffut posted, get an Intel mac.

 

[gugucom]

..Very likely the motherboard is the culprit, and even if not, you have at least two working CPUs for sure you can swap to check if it´s the CPU anyway - but Apples Service Diagnostics would have showed you this failure, so I am quite in doubts that any CPU is to blame here..

This is bad advise. I know for sure that Apple diagnostic CD does not recognise that sort of CPU failure. Listen to people with experience, not to those who have clever theories. Get one or more proper working CPUs by whatever means are suitable.