PPC G5 Halts, Panics, Crashes - heat related?

[UltraNEO*]

Hiya all, some of you might of notice I recently acquired a very, very cheap PPC G5 2Ghz (DP), sub $150 system).

Now as far as I'm aware this model doesn't have liquid cooled CPU's and thus those crashing ain't related to leakages, or are they?

So.. here's my dilemma, kinda odd behaviour if you ask me. : In a cool room, the entire system seem to boot up fine, be it a little slow, but that's because it's old :beige: everything will operate as expected. Running heavy applications with test documents open in photoshop and première is fine, no problems at all! It'll be happy running all day all night! Even past a 72hour soak test!!

However, when my studio gets warmer, usually when the central heating kicks it's a whole new ball game! After starting the system, it'll completely finish booting, then on the odd occasion it'll just halt xx( . Clock stops, mouse playing with it's beach-ball and so-forth - you get the picture. And other times, it'll panic and show a screen full of text over the desktop wallpaper..

Does anyone understand those errors? To me it looks like CPU0 is faulty.. but most crashes show that too!

 

[~Coxy]

It does sound like a bad CPU or bad RAM, unfortunately. If you have spare DDR anywhere, I would try that first. The heat-related symptoms does lead me to suspect that it's probably the CPU though.

 

[UltraNEO*]

Well, there's 4Gb of ram in there spread over six sticks - that's how it arrived.

Four of them seem to be stock Samsung stuff (what Apple seems to use) and the other two are Kingston modules.

Will it work with only two sticks in there? Or does it need a minimum of four?

...I think I need to spend some time with the machine for fault finding...

Kinda a waste to discard it, cost so little and it's almost working.. :lol:

 

[UltraNEO*]

Oh....

Does anyone have a copy of SMCfanControl for pre-intel machines? I'd like to bump up the fan speed see is it due to heat... might be a dry joint.

 

[JRL]

Good thing is that the processors aren't too expensive.

http://cgi.ebay.com/PAIR-OF-APPLE-POWERMAC-G5-2-0Ghz-PROCESSORS-630-6425_W0QQitemZ270463905178QQcmdZViewItemQQptZCPUs?hash=item3ef8e7ad9a

 

[UltraNEO*]

Good thing is that the processors aren't too expensive.
http://cgi.ebay.com/PAIR-OF-APPLE-POWERMAC-G5-2-0Ghz-PROCESSORS-630-6425_W0QQitemZ270463905178QQcmdZViewItemQQptZCPUs?hash=item3ef8e7ad9a

Thanks JRL. Before I dash out and buy them.. or one's what will ship to the UK. I wanna try problem solve it, even if that means grabbing the soldering iron.

Surely if the processors are faulty/dead, those crashes would happen continuously, on every single boot!!

But that's not the case, it only seems to be happening when it's running hot! Care to explain?

 

[coius]

check for dust in the heatsinks. Also, you may have to reapply CPU Grease, that may be the main issues if it's not dust when there is overheating

 

[Christopher]

the heatsinks could have lifted from the cpu's during shipping, you could check that.

 

[Gorgonops]

Here's a Macintouch page discussing "G5 Thermal Runaway". You might find something helpful in it.

On an advisory note, I had a 2.0 Ghz G5 Xserve for a while, which I understand uses basically the same CPU modules as the original G5 Desktops just with shorter heat sinks. I was warned at the time by the Apple engineer who gave the system to me that that the CPU modules were exceedingly delicate and that removing the heat sinks was a good way to destroy them. (Supposedly the naked CPU dies are *very susceptible* to being cracked or otherwise damaged by applying uneven pressure by over/under torquing the retention bolts.) For the record the Powermac G5 Service manual also claims that you *will* damage the processor if you separate it from the heat sink. Not "may", *will*.

If you Google you'll find people that *have* apparently gotten away with it (largely people trying to fix leaking 2.5Ghz watercooled models), but just be advised that from an official standpoint the magic smoke lives under the heat sink, no deeper. Of course, if it's broken anyway you don't have that much to lose.

The other thing to note that is in theory if you start swapping CPU modules you're *supposed* to run a "Thermal Calibration" program on them which is only officially available to licensed Apple servicemen. Undoubtedly there are... other ways... to find it, but that's an exercise for the reader. If you don't run that you may end up, among other things, with your CPU fans running at 100% speed *all the time*. (The Xserve I had would do that if it detected *any* anomaly in the cooling system, such as an unplugged fan on the other side of the case that had nothing to do with the CPU coolers.) Something to keep in mind if you start eBaying replacements.

In short, there are reasons the PowerMac G5 has a reputation of being something of a lemon. It is.

 

[Unknown_K]

G5's seem to be hot running chips, which is why Apple built the case around cooling them with massive airflow, multiple cooling fans, and temp sensors. When you resort to water cooling at the factory you know you will have issues down the road.

I guess if the computer lasted long enough to be out of warrenty then Apple did a good job?

 

[Mars478]

My iMac G5 of the same gen as your PowerMac using the same proc had this problem. It turned out to be RAM

 

[Gorgonops]

My iMac G5 of the same gen as your PowerMac using the same proc had this problem. It turned out to be RAM

Yeah. I suppose the real thrust of my post would be I would definitely try ruling out RAM and any other possible cause before ripping the CPU modules apart.

First thing I'd do is pull out the non-Apple RAM. I never added any RAM to that Xserve but some *extremely bad* experiences with PowerBook G4s of that vintage say you should always blame RAM first. I thought the SDR Macs were picky about RAM until I dealt with the first couple generations of Aluminum PBs. Ye gads. If you have the diagnostics/hardware test CD I'd definitely try running multiple cycles of the memory test program. (With those awful Powerbooks it wasn't unusual to have it pass once or twice before blowing up.)

(Of course, the "Bad RAM" would always work perfectly in a Dell notebook...)

While you're in there, blast some compressed air through the CPU heat sinks. Apparently they're quite effective lint traps.

 

[Mike Richardson]

In short, there are reasons the PowerMac G5 has a reputation of being something of a lemon. It is.

Only the water cooled G5s had huge problems. The other G5s didn't have nearly as many issues. The problem is that people only post when their computer is having problems. Nobody registers on a forum to say, "My G5 works fine".

 

[Gorgonops]

In short, there are reasons the PowerMac G5 has a reputation of being something of a lemon. It is.

Only the water cooled G5s had huge problems. The other G5s didn't have nearly as many issues. The problem is that people only post when their computer is having problems. Nobody registers on a forum to say, "My G5 works fine".

A little bird *very much in the know* once told me about a number of skeletons in the G5's closet, particularly the first generation (1.6-2.0Ghz) models, but that's about all I can say. It's probably just enough to warn anyone considering them that they're essentially exotic UNIX-workstation technology done on a shoestring budget. (At two grand-plus they may of seemed expensive, but a SUN Sparc machine in the same speed class would of been in the five figures.) And like anything done on a shoestring budget, there are... compromises.

Basically, they're the poster children for why Apple had to switch to Intel. Take that for what you will.

 

[Franklinstein]

The tower model G5s didn't have the same issues with the exploding capacitors, did it? If new RAM doesn't fix it, you might want to take a look at the caps, particularly those in the power supply regions of the logic board, and the power supply itself.

And like anything done on a shoestring budget, there are... compromises.
Basically, they're the poster children for why Apple had to switch to Intel. Take that for what you will.

Apple must do most of their engineering on a shoestring budget anymore, since there are also reports of problems across their post-PPC lineup, but mostly from the portables and the iPod/iPhone camps. I seem to remember the "mooing" MacBooks (among other issues with the 1st gen models), iPod nanos recalled due to exploding batteries, overheating iPhones, strings of iPhone updates that broke more than they fixed, display artifacts on the dual-GPU MacBook Pros, and stories of casing issues (cracks, warpage, discoloration, etc) across their product line. I guess swiching platforms can't fix half-assed engineering or cut-rate manufacturing and component sourcing.

Is it just me, or was Apple's best quality from about 1997-2001? This time period produced some amazing machines (2400, 3400, 9600, G3 desktops and notebooks, G4 towers), whereas after that, many problematic models (iceBooks, TiBooks) were introduced. Sure, there were some issues with the Rev. A B&W G3s or iMacs with bad flyback transformers, but nothing on the scale that filled forums like the dead-GPU iceBooks or leaking caps in the iMac G5s. I did like the AlBooks, though, because, aside from the whole failing lower RAM slot thing, they were solid, fast machines, very unlike the seemingly self-destructive TiBooks.

 

[Mike Richardson]

The tower model G5s didn't have the same issues with the exploding capacitors, did it? If new RAM doesn't fix it, you might want to take a look at the caps, particularly those in the power supply regions of the logic board, and the power supply itself.

My G5 motherboard has SMT capacitors that look exactly like the ones on older Mac motherboards which tend to leak after a while. I guess I've got another 10 years and then I'll have my G5 apart in pieces, replacing the capacitors xx(

The whole bulging capacitors thing isn't really Apple's fault. I think almost everyone was affected by that in some way.

Power supply issues in general - the power supplies are all made by third parties so you can pretty much blame those third parties. What didn't help though is when the PSU is in some funky proprietary shape (G4 MDD).

 

[UltraNEO*]

Here's a Macintouch page discussing "G5 Thermal Runaway". You might find something helpful in it.
On an advisory note, I had a 2.0 Ghz G5 Xserve for a while, which I understand uses basically the same CPU modules as the original G5 Desktops just with shorter heat sinks. I was warned at the time by the Apple engineer who gave the system to me that that the CPU modules were exceedingly delicate and that removing the heat sinks was a good way to destroy them. (Supposedly the naked CPU dies are *very susceptible* to being cracked or otherwise damaged by applying uneven pressure by over/under torquing the retention bolts.) For the record the Powermac G5 Service manual also claims that you *will* damage the processor if you separate it from the heat sink. Not "may", *will*.

If you Google you'll find people that *have* apparently gotten away with it (largely people trying to fix leaking 2.5Ghz watercooled models), but just be advised that from an official standpoint the magic smoke lives under the heat sink, no deeper. Of course, if it's broken anyway you don't have that much to lose.

The other thing to note that is in theory if you start swapping CPU modules you're *supposed* to run a "Thermal Calibration" program on them which is only officially available to licensed Apple servicemen. Undoubtedly there are... other ways... to find it, but that's an exercise for the reader. If you don't run that you may end up, among other things, with your CPU fans running at 100% speed *all the time*. (The Xserve I had would do that if it detected *any* anomaly in the cooling system, such as an unplugged fan on the other side of the case that had nothing to do with the CPU coolers.) Something to keep in mind if you start eBaying replacements.

In short, there are reasons the PowerMac G5 has a reputation of being something of a lemon. It is.

Thanks for the wise words. I don't plan to dismantle the machine unless it's a last resort. Why? Because for 90% of the time it's booting fine and it seems to work. The fans ain't ramping up at all.. though they are working. So naturally, i'm thinking those system panics are related to something else.

 

[techfury90]

A little bird *very much in the know* once told me about a number of skeletons in the G5's closet, particularly the first generation (1.6-2.0Ghz) models, but that's about all I can say. It's probably just enough to warn anyone considering them that they're essentially exotic UNIX-workstation technology done on a shoestring budget. (At two grand-plus they may of seemed expensive, but a SUN Sparc machine in the same speed class would of been in the five figures.) And like anything done on a shoestring budget, there are... compromises.

Basically, they're the poster children for why Apple had to switch to Intel. Take that for what you will.

I had a 1.6 until recently... that thing was utter garbage. It was easily beaten (performance-wise) by a 1.5 GHz G4 PowerBook I used to have. Terrible, terrible desktop performance. It also had annoying fan issues and strange power supply noises.

 

[LCGuy]

Is it just me, or was Apple's best quality from about 1997-2001? This time period produced some amazing machines (2400, 3400, 9600, G3 desktops and notebooks, G4 towers), whereas after that, many problematic models (iceBooks, TiBooks) were introduced. Sure, there were some issues with the Rev. A B&W G3s or iMacs with bad flyback transformers, but nothing on the scale that filled forums like the dead-GPU iceBooks or leaking caps in the iMac G5s. I did like the AlBooks, though, because, aside from the whole failing lower RAM slot thing, they were solid, fast machines, very unlike the seemingly self-destructive TiBooks.

Ehh, I wouldn't be so quick to say that...if anything, I'd say that Apple's best quality would've been from somewhere between 1987 and 1993. I remember my 1997 PowerBook 1400 had its logic board replaced twice under AppleCare, and its power adaptor replaced three times. It also went in for the issue with the CD bezel breaking off. That was just within the first three years. Then there's my iMac...which although has been trouble-free for most of its life, has had a couple of serious issues, mostly involving Open Firmware chucking a wobbly on a couple of my attempts at upgrading to 10.3. On the other hand, my MacBook is coming up to its 2nd year of ownership, and apart from the hairline crack near the rear vent, and a screw falling out about last year (which was replaced at the Apple Store when I was in Sydney), its been completely trouble free. I dunno, luck of the draw I guess.