Quad G5, Should I Buy It?

[star-affinity]

Before May of 2020 I used to run both my Quad G5 and my 2.3DC 24/7. Both those Macs have the special cable you speak of. Not once, for the three years those Macs were left on did they ever just suddenly shut off.

Is it possible that your work location might have had an aging electrical system or been overloaded? Of course, you could be right that it was some sort of hardware fault. But if multiple Macs were doing this I'd suspect something else.

It might be that we had a bad batch. But there were more than one that behaved the same way. Maybe they did offer it as a replacement or the problem weren't that drastic, but some kind of crash happened (this was during 2005 so don't remember exactly). I did conclude that whatever I did when it came to software didn't help.

I asked ChatGPT:

”Did the two core G5 Power Macs with 2.3 GHz processor that had a thicker power cable have some sort of power supply issue that was confirmed? I remember several of those at work during 2005 had some kind of problem that I as an IT technician wasn't able to fix. I think it was that they could shut down all of a sudden or some other kind of crash happened. Could go a couple of days where they worked fine so it wasn't consistent.”

The answer:

”Yes, the dual-core Power Mac G5 units, particularly the 2.3 GHz and 2.5 GHz models released in late 2005, were known to have some power supply issues. These issues often manifested as random shutdowns, crashes, or failure to boot. The symptoms you describe — sudden shutdowns or unpredictable behavior that seemed to resolve temporarily — align with these known problems.


Possible Causes:

1. Power Supply Defects:

• Apple used a new, more power-hungry design for the dual-core G5s, and some power supplies were prone to failure. The higher current draw could have stressed the power supplies, leading to instability.

• The thicker power cable you mentioned was introduced to handle the increased power demands safely. However, even with this improvement, power supplies occasionally failed.

2. Thermal Issues:

• Power Mac G5s were notorious for running hot. Although Apple introduced improved cooling systems, including liquid cooling for the 2.5 GHz model, thermal stress could still cause issues, especially over time.


3. Capacitor Failures:

• Like many computers from the mid-2000s, the Power Mac G5s were affected by the “capacitor plague.” Faulty capacitors in the power supply or on the logic board could swell, leak, or fail, leading to unpredictable system behavior.

4. Intermittent Electrical Faults:

• Aging components or minor design flaws in the power supply could cause intermittent electrical issues that were hard to diagnose.

Troubleshooting Back Then:

As an IT technician in 2005, diagnosing these issues would have been challenging without specialized tools. Random shutdowns or crashes often appeared like software issues, but hardware diagnostics wouldn’t consistently pinpoint the failing component. Apple did eventually acknowledge some of these problems, and there were repair programs for specific models.

Solutions:

• Replacement or Repair:


Apple often replaced defective power supplies under warranty or extended repair programs, though not all users were aware of these.

• Third-Party Repairs:

Some technicians replaced failing capacitors in power supplies and logic boards, but this required expertise in electronics repair.

• Monitoring Thermal Conditions:

Ensuring proper airflow and cleaning dust from the system could mitigate overheating, though it didn’t fully address the root issues.

If you were working with those systems back in 2005 and experiencing these issues, it’s likely the power supply or capacitor failures were at play. Unfortunately, without comprehensive diagnostic tools or extended warranties, these problems could have been difficult to resolve at the time.”

 

[ToniCH]

”Yes, the dual-core Power Mac G5 units, particularly the 2.3 GHz and 2.5 GHz models released in late 2005, were known to have some power supply issues. These issues often manifested as random shutdowns, crashes, or failure to boot. The symptoms you describe — sudden shutdowns or unpredictable behavior that seemed to resolve temporarily — align with these known problems.

Thanks ChatGPT, there were no dual-core late 2005 G5 Macs with 2.3 and 2.5 GHz processors - like you surely know. They were 2.0 DC and 2.3 DC. And like I posted the Quad had less PSU-problems than the DC-models.

But... as I have some weird crashes I haven't been able to diagnose and fix with my 2.0DC I guess it could be a good idea to take a look into the PSU. 👍

 

[BlueMacawBird]

I don't even know where to start with this…

First off, I'm not so sure anyone said to 'avoid the liquid cooled machines at all costs'. There were a few warnings about the LCS, but I don't recall those exact words.

I had zero issue with the LCS on my Quad. It was a university Mac, used by a professor, given to another professor who shipped it to me. Four years ago when I put it away it was still functioning perfectly.

I've never cared for the design of the G5, but it turns out I do have a favorite and that is the one that you apparently like the least - the 2.3DC. It was quiet, reliable, stable and never gave me any problems. I did have an issue with one drive not showing up whenever I restarted the Mac. However, having dealt with this SAME issue with my MacPro I now know it's a particular irritant of Western Digital hard drives, which I am partial to and which are mounted in this Mac. So, that issue was not the Mac.

With regards to the SATA connection, yes - you'd have problems. A lot of drives are SATA 2 or SATA 3 and the PowerMac G5 official specs say the G5 is SATA 1. Finding a drive that will automatically scale down or has jumpers can be hard. That's not the G5s fault.

Lastly, as I mentioned earlier, I ran both the Quad and the 2.3DC full power, 24/7 for at least three full years. Not once did the PSU go. When I put them away they were both still fully functional.

So, either you had an anomaly or I had an anomaly. Either way, my experience with a Quad and 2.3DC was not at all your experience.

OK, to be honest I do not have any personal experience with the LCS machines. However, when I was buying my DP machine about ten years ago from the world famous auction site, I saw more than a few machines that had visible LCS failures. Seeing that, and reading comments at the time about LCS potential issues, I chose to avoid them. And you are correct that while the thread did mention potential issues it did not present such a harsh view as I did. That was just my approach, chosen at the time I bought my DP machine. You and others clearly had a very good experience with the LCS machines.

The G5 only having a SATA I connection is not its fault, just something that has to be taken into consideration when / if drives are needed. I was lucky to find two that would work as the machine came to me without any drives.

And the machine that I liked the least was the G4 MDD, not the G5 LCS machines.

 

[TheShortTimer]

And the machine that I liked the least was the G4 MDD...

Why's that?

 

[eyoungren]

It might be that we had a bad batch. But there were more than one that behaved the same way. Maybe they did offer it as a replacement or the problem weren't that drastic, but some kind of crash happened (this was during 2005 so don't remember exactly). I did conclude that whatever I did when it came to software didn't help.

I asked ChatGPT:

”Did the two core G5 Power Macs with 2.3 GHz processor that had a thicker power cable have some sort of power supply issue that was confirmed? I remember several of those at work during 2005 had some kind of problem that I as an IT technician wasn't able to fix. I think it was that they could shut down all of a sudden or some other kind of crash happened. Could go a couple of days where they worked fine so it wasn't consistent.”

The answer:

”Yes, the dual-core Power Mac G5 units, particularly the 2.3 GHz and 2.5 GHz models released in late 2005, were known to have some power supply issues. These issues often manifested as random shutdowns, crashes, or failure to boot. The symptoms you describe — sudden shutdowns or unpredictable behavior that seemed to resolve temporarily — align with these known problems.


Possible Causes:

1. Power Supply Defects:

• Apple used a new, more power-hungry design for the dual-core G5s, and some power supplies were prone to failure. The higher current draw could have stressed the power supplies, leading to instability.

• The thicker power cable you mentioned was introduced to handle the increased power demands safely. However, even with this improvement, power supplies occasionally failed.

2. Thermal Issues:

• Power Mac G5s were notorious for running hot. Although Apple introduced improved cooling systems, including liquid cooling for the 2.5 GHz model, thermal stress could still cause issues, especially over time.


3. Capacitor Failures:

• Like many computers from the mid-2000s, the Power Mac G5s were affected by the “capacitor plague.” Faulty capacitors in the power supply or on the logic board could swell, leak, or fail, leading to unpredictable system behavior.

4. Intermittent Electrical Faults:

• Aging components or minor design flaws in the power supply could cause intermittent electrical issues that were hard to diagnose.

Troubleshooting Back Then:

As an IT technician in 2005, diagnosing these issues would have been challenging without specialized tools. Random shutdowns or crashes often appeared like software issues, but hardware diagnostics wouldn’t consistently pinpoint the failing component. Apple did eventually acknowledge some of these problems, and there were repair programs for specific models.

Solutions:

• Replacement or Repair:


Apple often replaced defective power supplies under warranty or extended repair programs, though not all users were aware of these.

• Third-Party Repairs:

Some technicians replaced failing capacitors in power supplies and logic boards, but this required expertise in electronics repair.

• Monitoring Thermal Conditions:

Ensuring proper airflow and cleaning dust from the system could mitigate overheating, though it didn’t fully address the root issues.

If you were working with those systems back in 2005 and experiencing these issues, it’s likely the power supply or capacitor failures were at play. Unfortunately, without comprehensive diagnostic tools or extended warranties, these problems could have been difficult to resolve at the time.”

I have been on MacRumors since August 2011. I've owned a 2.3DC G5 since mid-2016 and a Quad since February 2017. Not once in all this time did I ever hear there were PSU issues.

I am not saying you're wrong and I am not denying any evidence you have or might in the future post. I am just remarking on this, because this would have nice to at least be aware of when pursuing these Macs. I don't deny what you've posted, I just have to assume that I got two good G5s that did NOT have these issues. My 2.3DC was a $50 school district purchase (local), so I have to assume it was taken care of by an IT department. Same with my Quad, only that was a state university.

Maybe stuff did get replaced before I got these Macs and therefore I have benefitted, IDK.

Thanks for the info.

 

[redheeler]

Thanks. I have a couple of PPC systems: A 1.8GHz G5 and a 1.67GHz PowerBook G4. I just thought, if the price were right, of adding the king. The problem with the king is the problematic cooling system which has kept me from acquiring one.

I built a quad out of parts I bought and a dual-core system as a base. Didn't take long for the thing to start overheating and it was back to dual-core.

People have had success running quad CPUs as a dual-core 2.5. Seems like a good compromise. Not a lot you can do with these Macs nowadays anyway, aside from some retro gaming and running those coveted non-subscription versions of software like MS Office and the Adobe suite.

 

[eyoungren]

OK, to be honest I do not have any personal experience with the LCS machines. However, when I was buying my DP machine about ten years ago from the world famous auction site, I saw more than a few machines that had visible LCS failures. Seeing that, and reading comments at the time about LCS potential issues, I chose to avoid them. And you are correct that while the thread did mention potential issues it did not present such a harsh view as I did. That was just my approach, chosen at the time I bought my DP machine. You and others clearly had a very good experience with the LCS machines.

The G5 only having a SATA I connection is not its fault, just something that has to be taken into consideration when / if drives are needed. I was lucky to find two that would work as the machine came to me without any drives.

And the machine that I liked the least was the G4 MDD, not the G5 LCS machines.

There were (as I understand it) two different LCS production runs for the Quad. The difference was either one or two pumps and I totally do not recall which one was the 'good' system and which one was the 'bad' system. But, Apple redid the LCS system because of early problems. So, in this instance you have a case here. The later production runs had the improved LCS.

I just simply never questioned what I had because I trusted the person who sent me the Quad and in the three years I was using it daily, I never had a problem with the LCS.

Now, I DO have a 2.7GHz Dual Processor G5 with an LCS and it was given to me in full understanding that the LCS needed to be fixed/reworked. The member here who gave it to me had plans to do that but never got around to it. I never saw that LCS as leaking or anything else wrong, but I know it has to be redone because any stress on the CPUs causes it to heat up fast and turn off.

So, yeah, the Dual Processor 2.7 DID have LCS issues. And that I do not deny.

 

[ToniCH]

I have been on MacRumors since August 2011. I've owned a 2.3DC G5 since mid-2016 and a Quad since February 2017. Not once in all this time did I ever hear there were PSU issues.

Neither have I, until today. And I was around G5s when they were new. Do not remember single one that would have experienced a broken PSU during those years (I wasn't that active with them in the late 2005 anymore so maybe that is why?). But, there clearly was lots of problems like the statistics in the link I provided shows. There isn't much talk about G5 PSU problems in modern days but maybe most of the machines still running already have repaired PSUs? And if the problem was the capacitors, good ones are not so eager to blow.

G4 MMDs are also notorious having PSU problems (mine is starting have them too). They are mostly capacitor problems so quite repairable if caught before everything else burns.

 

[BlueMacawBird]

Why's that?

I have two G4 MDD machines, they were among the first vintage Macs in my collection. When they ran they were hot and noisy, but reasonably fast. I had a lot of fun with them. The biggest issue was the PSUs would fail. I found a guy on eBay who would refurb them on an exchange basis for about $90 each. The repaired items ran for a while but also eventually failed. I suspect they did not get a full overhaul and recap, but the guy did the minimum to get them out the door. Anyway the machines wound up being frustrating and expensive. I concluded that the earlier Quicksilver machines were a far more sustainable choice and I have two of them. One is permanently set up in my basement, and used to run vintage games. It's a 933 Mhz singe processor machine with a 20" Cinema display. The QS is also not as densely packed as the MDD and is a bit easier to work on.

 

[m1maverick]

I built a quad out of parts I bought and a dual-core system as a base. Didn't take long for the thing to start overheating and it was back to dual-core.

People have had success running quad CPUs as a dual-core 2.5. Seems like a good compromise. Not a lot you can do with these Macs nowadays anyway, aside from some retro gaming and running those coveted non-subscription versions of software like MS Office and the Adobe suite.

Long ago I ruled out getting an LCS G5 PowerMac, especially since it would see little use. However, when this popped up I thought maybe I would add it to my collection just to have the top of the line model.

My plan, had this been a quad as the listing states, was to reach out to the seller to see:

1. Would it be possible to stop by and examine the system before committing to it. Not sure if that would be possible as it would require bypassing Ebay. Not so much as to do the transaction outside of Ebay but rather inspect it.
2. See if they would be open to an offer. I didn't feel like spending $200 for it, I was thinking maybe $100 would be appropriate.

Since it's not a quad and given how strongly a lot of people feel about the LCS I've lost interest in it. I already have two PPC systems which see almost no use.

 

[TheShortTimer]

I have two G4 MDD machines, they were among the first vintage Macs in my collection. When they ran they were hot and noisy, but reasonably fast. I had a lot of fun with them. The biggest issue was the PSUs would fail. I found a guy on eBay who would refurb them on an exchange basis for about $90 each. The repaired items ran for a while but also eventually failed. I suspect they did not get a full overhaul and recap, but the guy did the minimum to get them out the door. Anyway the machines wound up being frustrating and expensive. I concluded that the earlier Quicksilver machines were a far more sustainable choice and I have two of them. One is permanently set up in my basement, and used to run vintage games. It's a 933 Mhz singe processor machine with a 20" Cinema display. The QS is also not as densely packed as the MDD and is a bit easier to work on.

Thanks for such a detailed reply.

This really good to know. I can't see myself picking up any further G4 desktops but if I do, I'll be wary of the MDD range. Should I come across a dead unit that's free or cheap, the resurrection work might be worthwhile for the fun of an electrical engineering project.

I've got a relative who has one that was in constant usage everyday within a professional, commercial environment. I'll have to ask whether their machine is still working and if they experienced any PSU problems.

G4 MMDs are also notorious having PSU problems (mine is starting have them too). They are mostly capacitor problems so quite repairable if caught before everything else burns.

Does this basically require through-hole desoldering work by any chance?

 

[ToniCH]

Thanks for such a detailed reply.

This really good to know. I can't see myself picking up any further G4 desktops but if I do, I'll be wary of the MDD range. Should I come across a dead unit that's free or cheap, the resurrection work might be worthwhile for the fun of an electrical engineering project.

I've got a relative who has one that was in constant usage everyday within a professional, commercial environment. I'll have to ask whether their machine is still working and if they experienced any PSU problems.



Does this basically require through-hole desoldering work by any chance?

There are 2 versions of the MDD PSU, one made by Samsung and another ACBel. If one recaps it before it blows its quite likely that nothing else needs to be renewed. If it's already blown then there might also be transistors etc. that have gone too. The caps are normal electrolytic through the hole stuff so nothing too bad. The electrolytics could be replaced with other compatible styles too.

But, there are lots of them and the PSUs are quite cramped. I counted almost 30 caps in the ACBel PSU. There are 12 that should be swapped in any case but the others can be bad too.

Easier but not museum quality option is to replace the PSU with an ATX PSU. The cables are not 100% compatible but there are instructions in the net how to make an adapter or swap the wires in Mac connector so everything is correct. Also, you can buy a ready made adapter cable from ebay. This solution usually deletes the option to run ADC-displays as there is no 25V output from ATX PSUs (this from memory, I could remember it wrong). But, in my case I use a G5 GPU in my MDD which cannot power ADC-display in MDD anyway so no biggie.

 

[TheShortTimer]

This solution usually deletes the option to run ADC-displays as there is no 25V output from ATX PSUs (this from memory, I could remember it wrong). But, in my case I use a G5 GPU in my MDD which cannot power ADC-display in MDD anyway so no biggie.

That's something I'd be able to live with quite happily as I don't own anything ADC related and have little desire to ever do so.

 

[ToniCH]

That's something I'd be able to live with quite happily as I don't own anything ADC related and have little desire to ever do so.

Another advantage of using ATX PSU is that you could install more powerful one than the Apple originals (AcBel is 400W only, Samsung is 360W), plug in all the possible expansion cards and still it would not over stress the PSU and it would probably last forever.

And the Apple originals (especially ACBel) are responsible for the loud fan noise they are famous for, that would also be fixed with the ATX PSU.

 

[TheShortTimer]

Another advantage of using ATX PSU is that you could install more powerful one than the Apple originals (AcBel is 400W only, Samsung is 360W), plug in all the possible expansion cards and still it would not over stress the PSU and it would probably last forever.

And the Apple originals (especially ACBel) are responsible for the loud fan noise they are famous for, that would also be fixed with the ATX PSU.

Wait, so if I replace the original PSU in my QuickSilver with an ATX unit, that would eliminate the horrendous aircraft engine noise that drowns out all sound in the computer's vicinity?

 

[Rychiar]

for what purpose?

 

[ToniCH]

Wait, so if I replace the original PSU in my QuickSilver with an ATX unit, that would eliminate the horrendous aircraft engine noise that drowns out all sound in the computer's vicinity?

Yes, if the noise is caused by the psu fan or fans. You can buy quite silent ATX PSUs.

 

[TheShortTimer]

Yes, if the noise is caused by the psu fan or fans. You can buy quite silent ATX PSUs.

You've provided me with the inspiration for an EE project.

Thanks!

 

[typonaut]

Another easy way to tell if you have a Dual Core Mac is if there is a white plastic strip in the back. All three DCs have an integrated BT/Airport card (connected to a ramp card, which actually IS rare) and this plastic strip is what allows them to send/receive.

If that exists then you either have a 2.0DC, 2.3DC or a Quad. No other model G5s have this strip.

The other clue to this last generation of G5s is that they don’t have the standard IEC C13/14 power cable/socket, but instead have a chunkier IEC C19/20 – I don’t think any other Mac has this.

 

[Doq]

Also while the LCS on any G5 (not just the Quad) can fail you don't really have to fix it. There are options besides "rebuild the LCS".

QUAD G5 AIR COOLED (dxf included)

It first started when I bought a quad core logic board to fix my broken dual core g5. Then I said to myself: wait a minute, I could convert my dual to quad! Then soon, I bought a quad with a broken lcs. Then I said to myself: wait a minute, I coud convert my quad to air cooling !! So here ya...

forums.macrumors.com

https://forums.macrumors.com/threads/2427612/

(done shilling.)

 

[barracuda156]

But…it's not a Quad. The listing is for a dual processor.

Or were you just remarking in general that $200 for a Quad is a decent price?

Yeah, I meant it is decent for the real Quad (or perhaps 2.7 DP).

 

[AF_APPLETALK]

If you really want a G5 I would rather recommend choosing one of the other two late 2005 models: the 2.0DC or the 2.3DC.

Of course the Quad is faster and its the top of the line but also brings lots of potential trouble and hassle with it. The water (read: acid ) cooling must be rebuilt ASAP or it will leak and damage/destroy the machine. Even the tiniest of leaks will damage the cpu cards long before you notice anything. And it might have done it already in some degree when you get your new machine. And this project is quite a lot of work and not always simple.

Pricing: this varies but I see G5s going for 0-50€ usually and very rarely 100€.

I appreciate the simple design of everymac's website. That they didn't change it brings back a bunch of memories of a more wholesome feeling Mac community

 

[star-affinity]

Thanks ChatGPT, there were no dual-core late 2005 G5 Macs with 2.3 and 2.5 GHz processors - like you surely know. They were 2.0 DC and 2.3 DC

ChatGPT again responding to your correction.

”You’re absolutely correct—thank you for pointing that out! The dual-core Power Mac G5 lineup released in late 2005 included the following configurations:

1. 2.0 GHz Dual-Core (single dual-core processor).

2. 2.3 GHz Dual-Core (single dual-core processor).

3. 2.5 GHz Quad-Core (two dual-core processors).

There was no 2.5 GHz single dual-core G5. The 2.5 GHz model was the Quad-Core variant, which used two dual-core processors, making it a distinct model in the lineup. The confusion likely arose from mixing up these configurations.

Revised Points:

• The 2.3 GHz Dual-Core G5 was indeed a single dual-core model.

• The 2.5 GHz G5 was exclusively the Quad-Core model with dual dual-core processors.

• Both the 2.3 GHz Dual-Core and 2.5 GHz Quad-Core models were known for potential power supply issues, as discussed.

Thanks again for clarifying! It’s important to keep these details straight when looking back at these machines.”

I have been on MacRumors since August 2011. I've owned a 2.3DC G5 since mid-2016 and a Quad since February 2017. Not once in all this time did I ever hear there were PSU issues.

I am not saying you're wrong and I am not denying any evidence you have or might in the future post. I am just remarking on this, because this would have nice to at least be aware of when pursuing these Macs. I don't deny what you've posted, I just have to assume that I got two good G5s that did NOT have these issues. My 2.3DC was a $50 school district purchase (local), so I have to assume it was taken care of by an IT department. Same with my Quad, only that was a state university.

Maybe stuff did get replaced before I got these Macs and therefore I have benefitted, IDK.

Thanks for the info.

Great to hear it's been stable for you!
It was a long time ago now, but I do remember this was a real problem at work on on the ”thick cable” Power Mac G5's we had.

Found this at Apple Discussions from 2007:
Dual 2.3 GHz G5 suddenly shutting down

Dual 2.3 GHz G5 suddenly shutting down - Apple Community

discussions.apple.com

Also these comments by ”cube” in a thread here on MacRumors from 2009:

The 2.3 dual core power supply looks very bad in the 2006 macintouch survey.

https://forums.macrumors.com/threads/how-reliable-are-dual-core-powermac-g5s.750488/post-8130696

But the dual core power supply looks really bad, both from the old survey and from the ongoing user reports.

https://forums.macrumors.com/threads/how-reliable-are-dual-core-powermac-g5s.750488/post-8131015

When you see the massive difference in reliability of the power supply compared to the other G5's that were part of the survey, you know something is actually going on.

It does not help either that Apple had a power supply replacement program for the dual cores.

https://forums.macrumors.com/threads/how-reliable-are-dual-core-powermac-g5s.750488/post-8138037

Found this from 2006 on ArsTechnica:

Get your Power Mac G5’s power supply fixed

Get your Power Mac G5’s power supply fixed

Apple has launched the Power Mac G5 Repair Extension Program for Power Supply …

arstechnica.com

 

[eyoungren]

Yeah, I meant it is decent for the real Quad (or perhaps 2.7 DP).

As an owner of a 2.7DP, there's no way I'd ever pay $200 for it. While mine was free and basically driven to me within 100 miles of my home and I'm grateful for it, I still would not pay that.

Just me.

 

[eyoungren]

You've provided me with the inspiration for an EE project.

Thanks!

ATXG4

Owner of this website used to actually offer the conversion cables for sale. They stopped doing that a long time ago, but the site is still up so others can see how to do it. It's all documented…

EDIT: Hmmm, getting some errors on the links so might have to run this through the Wayback Machine.