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

I use a G5 PowerPC 970 (2.2), 2 GHz, with 3.5 GB RAM for graphic work and prepress processing in a print shop in south west Virginia.

My G5 uses a partitioned hard drive for OSx (10.5.6) and stores the original OS on a separate internal HDD (mainly used for storage and back-up incase of a HD crash.) My co-worker stores all of the important customer info and fonts on his Mac (luckily) so there is not much on my Mac that would cause a HDD failure or any "Stress" on my system at all for that matter.

Originally (a few months back) the computer's fan would "flair up" after falling into sleep mode and the computer would not respond to any wake-up attempts.. Initially, I had never linked the Sleep-mode issue to the kernal-trap errors, but after reading this thread, I am certain the two are related.

Out of the blue, my G5 crashed during operation (about an hour in) with a kernel report taking up the top-left hand side of the screen. I didn't think anything of it and upon restarting the system, it ran fine for days, (possibly weeks even)... until one day, when after trying to process a simple Excel spreadsheet, the system crashed again. My mouse froze and a flash of a kernel trap again appeared across my screen... never the less, My Mac has given me **** ever since. I can still boot from the ** thing (and it seems that I still show 2 processors) yet booting consists of several attempts and a lot of frustration.

My original diagnosis was the hard-drive.. I expected it had crashed and had also expected it to be an easy fix, yet after several tests and external boots (Via Installer CD, etc).. the system was still buggy. We eventually initiated a system re-install.. (had to use keys to force boot computer) and even tried booting from the old OS HDD... nothing seemed to work (Which leads me to believe that it has nothing to do with the software.)

Now, I am not sure why, but I can still (after several attempts) manage to boot from this G5... but after reading this forum, I realize that this may be short lived.. This is highly annoying.. and with such a deadline oriented "work structure" I may be in for some trouble when it finally decides to "kick the bucket." Apple Care has also expired for the Mac and I am unsure of my employers willingness to purchase a new computer (this could leave me in a VERY akward position)... It saddens me that a otherwise excellent computer could be rendered useless do to Apples negligence..

Strangely enough... leaving the system on seems to be a decent alternative to trying to reboot it.. although I feel this is probably more harmful in the long run.

Add me too the list. I just spent hours reading all the information online and speaking with Apple on the phone (very unhelpful). This is frustrating as I have been a big Apple evangelist in the past, and this is not the first major production flaw I have had in an Apple product. This is the third time it has happened. First a mac mini drive was bad and I didn't have apple care and it died 13 months after purchase. The second was with an ipod mini, just about a year after it was purchased. And now the G5 PowerMac... 10 months after the end of my Apple Care and 25 days after they closed a recall they had on these models. I am very nervous about spending any more money with Apple, but if I do it will be the cheapest base model. They should step up and take responsibility, like Toyota.

Hello,

after spending around 3 full days on the www I found the solution to my Problems on my G5 Quad (it did not want to start anymore, red LED bright, fans roaring after 2 minutes)
Message "still waiting for root" in verbose mode (APPLE-V during bootup)

I did all the tests that I could find on the WWW. I even took the watercooled processor unit off (Do NOT attempt the same without proper instructions from the "Mac-G5Service-Repair-Manual.pdf" which I downloaded from
http://www.scribd.com/document_downloads/
, otherwise you might spoil everything) The cooling unit was in perfect condition, like new.

So, after all "standard tests" I phoned www.golytronic.de , a German company pecialized in Mac repairs.

The Problem lies in soldering joints on the main board, in the area between memory card section and processor section, just underneeth the heavy aluminum cooler.

The proof is simple: Power off, just take your hair dryer and warm the main board up at full power for about 60 seconds. Put the fan unit and the acrylic wind shield back in place. If the G5 is booting now and behaves normal, your know the location of the error.

According to www.golytronic.de you should not wait with a thorough fix, otherwise the error may get worse and become a non repairable state.
They offer a resoldering at a very moderate 150 to 280 EU, depending on how many attampts are necessary. They even give you a warrenty of a half or full year.


I hope this may help somebody.

WiLi

PowerMac G5 Dual 2GHz freezes any time - Turn on your computer, start the system, within 2-5 minutes freezes, it can only off button.
RAM is okay, HDD testing and it works - I suppose I have a similar problem with the processor.
I am very pleased, especially after having experienced and iBook G3 900MHz http://geektechnique.org/projectlab/726/diy-obsolete-ibook-logic-board-repair (uncorrected) and the graphics card and iBook G4 1.2 with a similar problem, it I corrected myself http://macintoshhowto.com/hardware/how-do-i-get-my-broken-g4-ibook-fixed.html.
I applaud Apple, well, hw himself and produces more miserable - perhaps not even possible.

Hello all,
I have the joy of working with 70+ G5s at work. We have had several of them have this problem. I didn't look at all the posts, but has anyone looked for the red LED under the Heat sync (you have to look through the front to see it). From what I've been able to find, that LED is an indicator of a bad CPU, OR a faulty temp probe. If the temp probe fails, the Mac goes into a fail safe that acts like a freeze or bad crash. the problem is that it doesn't reset. On some (not all) of our G5s, a SMU reset, PRAM reset, and TOD battery removal when the mac is unplugged for ten minutes reset the probe. The other G5s that didn't work on are now spare parts. I wish Apple wasn't so secretive about its logic board layout and diagnostic systems on 5+ year old systems it doesn't even support anymore.

Just wanted to add my name to this list. I bought the MAC in the summer of 2006...this is my first MAC, so I'm not even sure how to do all of these repairs discussed in the forum. It used to have times where it wouldn't turn on, but I'd wait for a bit, then it would be fine. It freezes sometimes, then because unable t turn on. Today, I'm not able to get it on, and I've unplugged it for various durations all day up to an hour, and it will freeze at the white apple screen or not turn on at all. I can't afford a repair at this time, so it's a bummer. My HP from 2001 running Windows ME still works. This might be wishful thinking, but is there any chance of apple fixing this for free considering it's a common problem? This was a really freakin' expensive computer, and I also bought the cinema display monitor.

Thanks!
Kozak

Hi Kozakistan, and a warm welcome to the forums! 🙂

I feel your pain, but see...

http://www.xlr8yourmac.com/archives/feb10/021010.html#S26535

Unfortunately, I'm adding my Power Mac Dual 2.5GHz G5 to the list that have fallen victim to what appears to be a processor with a time bomb designed in.

I purchased the G5 new in 9/2004. It performed well until 9/2009 when the liquid cooling system sprang a leak destroying the logic board, both processors, and the power supply. The local Apple authorized repair shop gave me a $2088 estimate to replace the parts. Even though out of warranty, I called Apple and they agreed to pay for the repair cost.

I upgraded to Leopard and the repaired G5 ran well until 1/2010 when I started getting random freeze-ups. The system just locks up. The display is frozen, and the G5 doesn't respond to the mouse keyboard. The fans go into turbo mode. The only way out is to hold the power button in. I thought there be software problems. However, the freezes continued randomly after changing disk drives, installing good backups, and even once when installing the OS from the DVD. The ASD tests pass once the G5 becomes reasonably stable.

The G5 is still limping along but it's no longer is my primary computer. It seems to run with less freeze-ups once I get through enough freeze/forced power down/power up cycles and leave it powered on. From a cold start, it usually will freeze within a few minutes.

From the information gleaned from this thread, the problem sounds like it could be the result of the weak bond between a processor chip and the board.

I'm not putting any more money into this machine, but it bugs me that I still have a 1 GHz PC that has run 24/7 since 1999 and have had to replace only its graphics board, but have an Apple system that failed at the CPU in 5 years.

My 2.7 GHz dual-CPU G5 (Early 2005 model) had an LCS leak at its O-ring seals. The only symptom was a failure to re-boot once the computer had been on for 10 minutes or more. If left on, it continued to run normally. I repaired it myself and documented the repair. If anyone is interested, you can read my article on this "XLR8yourmac" web page:

http://www.xlr8yourmac.com/systems/G5CoolantLeak_Repair/G5_CoolantLeak_Repairp1.html

Thanks to Mike for posting it!

Add me to the list, the same problems here - see my previous postings at

http://discussions.apple.com/thread.jspa?threadID=2510666&tstart=0
http://discussions.apple.com/thread.jspa?threadID=2526517&tstart=0

I switched to Macs when System 7 came out, since then I have equipped offices with tons of Macs, have generated lots of new customers for Apple and, finally, have purchased LCs, Power PCs, G4 and G5 computers as well as PowerBooks and MacBooks for personal purposes.

Apple, this is YOUR web site,
this is YOUR discussion page,
this are YOUR customers all sharing the same systematical issue with YOUR product.

Current Apple managers should read "Selling the Dream" from Guy Kawasaki - did you ever hear about him? If not, Steve will tell you and he will explain to you what the Apple evanglism means, i.e. "the process of convincing people to believe in your product or idea as much as you do." Guy also said: "don't forget your friends".

There I was, happily using my G5 7,3 Dual 2Ghz (June 2004) 10.5.8 when there was a security, JS, & iTunes update. So I do the update, as you do, and restart. This was followed by a panic attack half way through rebooting. Since then I have been only able to get it started a few times - each time with a panic attack or a complete freeze.
So I take out the HD and put it into another G5, test it, reinstall it etc. Works perfectly on the 2nd G5. Put it back - no change. Try another (original) HD. No change.
Remove ram except Apple Ram. No change. Change Apple ram, for I stick of crucial. No change.
Clean everything. No change. Tried unplugging and the PMU button. But no change.
I have reset NVRAM via open firmware which gets it going but then it freezes before anything useful can be done.
Although I did note temperatures thus:
HD 37
CPU A 52
CPU A ambient 30
CPU B 42
CPU B ambient 28
BackSide 41
DriveBay 24
U3 Heatsink 64

Booting from the CD doesn't work, or at least it worked once but had a panic attack on selecting the language option. Often boot up options like Boot D, or Single User Mode just does not seem to work. Boot mouse key always works though:-?

Bootups vary from a blank screen, to just the grey apple screen, to occasionally showing what looks like an old OS9 symbol, followed by the grey apple screen.

I shall try some of the suggestions in this forum, like changing the battery, and setting it to run on one processor. I suspect the answer is the logic board has gone. I'm not sure its worth sending it from the UK to Germany for a fix. Shame, as it was a nice machine.

I think the conclusion from this thread is to buy only with applecare and sell after 3 years.

Also, try disconnecting the Hard Drive & see if it boots OK from the Install Disc.

AJ500, do you mind my asking what you told Apple to convince them to cover the cost of your leaky G5? Did they put up much a fight?

Hi All,

Just adding my name to the list of broken G5 Dual 2.0Ghz (2005 model) system owners, due to the suspected logic board soldering issue.

I'm a theoretical chemistry graduate student, and have recently inherited the computer from my research lab. Up until last week, we had been actively using the system for simulations. Our on-campus repair service took a look at the computer when it began acting up; their response was that the logic board needed replacing (for an excessive price), and so we ended up just investing the money into a new iMac 27" quad-core instead.

In hopes of getting the PowerMac to work again on my own, I researched the symptoms and possible causes online over the weekend. The issue is exactly as described and encountered by other G5 Dual 2.0 owners throughout this thread:

1 - The system hangs at random parts of the boot process. Either no gray Apple loading screen appears, or it appears and then locks up mid-way through the boot process.

2 - When the system does manage to make it through the boot process, the system (as reported by System Profiler) will either report one or two processors. If both are reported, then the system is destined to freeze at a random elapsed time afterwards; however, the system seems "stable" (relatively) when just one processor is reported (i.e. it doesn't freeze after a random amount of elapsed time). A reboot of this "working" state brings you right back to #1 above.

3 - In suspecting an issue with the soldering of the chip between the RAM region and processor heat sinks, I tried heating that portion of the logic board with a hairdryer. In each of the several tests, the system successfully booted with both processors reported by the System Profiler. However once the logic board cooled down (while powered on and booted into the OS), the system freezes and it's back to #1 above.

Even though the system is five years old it is still an excellent and capable machine. Thus it's a shame to see it fail so suddenly, especially due to a logic board issue of all things. For the premium cost, one would expect that it should last much longer than this.

I hope that Apple will become cognizant of this widespread problem and offer to replace these logic boards in an affordable (realistic) way, so that these great systems can continue to be used to their potential.

Nick

Hi Nick, and a warm welcome to the forums! 🙂

While you may get help or a solution here, It's quite acceptable to start a new topic of your own, certainly feel free to start a new topic to attract more helpers to your particular situation, on this side it gets hard to respond to more than one person at a time & their particular situation, here's a link if as is often the case, it's hard to find out where to do it...

http://discussions.apple.com/post!default.jspa?forumID=596

Have you tried moving the RAM pairs outwards? It's worked for several people. 🙂