Just picked up a 2.7GHz PowerMac

[ITguy2016]

Just picked up a 2.7GHz PowerMac G5. Typing this post on it now. Pretty much a stock configuration though I had to use the hard drive out of my recently deceased 2.0GHz system Case is in rough condition, inside is dirty so it needs a little cleaning. Everything appears to work though the fans spin up and down (maybe will stop once cleaned?)

Since this system had the LCS I am concerned about potential failure. Almost didn't buy it for that reason but for $60 I figured why not? It's the top of the line G5 for single core performance. Upon inspection one of the power supply screws appears to have some corrosion on it. I can't say if it's from a leaking LCS or merely because it has been in storage for a while.

What steps can I take to minimize any chance of LCS failure?

 

[jbarley]

Check "System Preferences" under "Energy Saver"
If Automatic is selected that can cause fan surges, select either Max or reduced and the fans will settle down.

 

[ITguy2016]

Just complete a thorough cleaning and it appears the LCS is or has leaked at some point in the past. There are obvious traces of corrosion on the rear lower frame, rear lower foot, and the previously mentioned power supply mounting screw. Furthermore when I blew it out with compressed air little specks of white and "red" flew out of the system which I suspect those were flakes of corrosion and rust.

The system is operational and appears to work fine except for the fans spinning up and down. Most likely having to do with the lack of (or low) coolant in the LCS. Question is: Should I investigate further or just leave it alone? Perhaps all the damage that would be done is already done. Though I suspect at some point it's going to give up the ghost. The only real way to know how extensive the damage is is to disassemble it for a close inspection. Perhaps I can learn how on my dead 2.0 GHz system. If the power supply numbers are the same then I have a spare power supply should this one eventually fail.

Thoughts?

 

[Altemose]

Question is: Should I investigate further or just leave it alone?

Yes. The LCS is going to need a complete rebuild. @gavinstubbs09 has a lot of experience in the rebuilds of those systems, and may be able to share some tips on the parts needed and proper procedures. You will likely need to seek his guidance on how to bleed the system, as an air pocket will impair the cooling ability.

 

[bunnspecial]

I need to break down and rebuild my 2.7.

Congratulations on getting the fastest single-thread PPC Mac ever built. Aside from the LCS issues, they are great Macs.

If I can ever get a SCSI card that will work in a G5 and doesn't have an impossible to find external connector(I have a card now that satisfies the first but not the second requirement) mine will likely replace the Quicksilver I'm currently using for scanning duties.

 

[ITguy2016]

Yes. The LCS is going to need a complete rebuild. @gavinstubbs09 has a lot of experience in the rebuilds of those systems, and may be able to share some tips on the parts needed and proper procedures. You will likely need to seek his guidance on how to bleed the system, as an air pocket will impair the cooling ability.

Thanks for the recommendation and pointing me to gavinstubbs09. Still trying to decide if I want to bother with it or just risk using it as is. Sometimes my cures can be worse than the disease. Though it might be an interesting undertaking.
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Congratulations on getting the fastest single-thread PPC Mac ever built. Aside from the LCS issues, they are great Macs.

Thanks. The fastest PPC was one of the reasons I decided to buy it. I can't say I've ever seen one for sale, at least locally. The LCS is one of the reasons I wanted to avoid it. Too bad the LCS systems weren't more reliable.

 

[bunnspecial]

As a side note, you can also fit the fastest retail(non-flashed) GPU to these computers-the X850XT. My dual 2.7 has an X800XT in it now, although I know one MR member who got very lucky and got a 2.7 with a BTO X850.

I have all the BTO/Retail PCIe G5 GPUs(although an FX4500 isn't in my hands yet) and the X850XT trumps them all.

 

[ITguy2016]

Thanks for the information Bunn...not sure I'm willing to invest money into an upgraded GPU until such time as the system has proven itself operational over the long haul.

 

[Altemose]

Thanks for the recommendation and pointing me to gavinstubbs09. Still trying to decide if I want to bother with it or just risk using it as is. Sometimes my cures can be worse than the disease. Though it might be an interesting undertaking.

The way you need to look at it is that with the LCS running with less coolant then full capacity, that coolant is heating much more and has a lot more air in the system. The leak is only going to progress, so it must be fixed right away.

 

[Dronecatcher]

Evidence of a leak could also indicate the LCS has been rebuilt and repaired already.
The fans on my Dual 2.3 G5 go up and down all the time unless I set the performance setting to "reduced" - in contrast, my Quad is virtually silent even when under load - seems to be some G5s are like that.
I wouldn't worry, if your objective is to have a useful computer rather than an exhibition piece, save money and use it until it dies.
I never even considered the state of the LCS on the two Quads I bought - they're old computers bought for next to nothing - what can you expect?
Unless you're heavily into gaming, don't waste money on a new GPU - there's no benefit whatsoever, unless your base card has 64Mb then going to 128Mb will help the GUI be more snappy.

 

[ITguy2016]

The way you need to look at it is that with the LCS running with less coolant then full capacity, that coolant is heating much more and has a lot more air in the system. The leak is only going to progress, so it must be fixed right away.

Is there any way to check the coolant level?
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Evidence of a leak could also indicate the LCS has been rebuilt and repaired already.

I was thinking this too. I did see a couple of white, round stickers with initials on them. The kind which technicians tend to place in a system indicated some form of work had been done.

My train of thought is two fold:

• It's working so leave it be. The possibility all the damage that would have been done has already been done (i.e. whatever coolant has leaked out is already out and no more is left to leak...though then there's the question of overheating).
• There's the possibility more damage could result and eventually result in the system completely failing. Thus be preventative and rebuild the LCS.

Both situations depend on the existing damage. Is the LCS leaking? If so has all the coolant leaked out already? If not will it continue to do so? Has the LCS already been rebuilt? There are definite signs it has leaked in the past. Without tearing into it I can't say.

Removing the system seems straight forward except for removal of the CPU covers (same issue I mentioned when I posted about my failed 2.0GHz G5). Aside from that all I need is a really long torx driver...something I can pick up for cheap. I guess what I'll do is use the 2.0GHz as a learning system on how to pull it apart. Once I know the steps I can pull this system apart to examine it.

 

[bunnspecial]

If you EVER think you might take an interest in compact Macs, go ahead and invest in a good 12" long or longer T-15 Torx driver. This is an essential tool for opening compacts, and can make life easier on other Mac repairs. Offhand, mine has helped me remove LCSs and also swap CPUs on Mac Pros.

 

[ITguy2016]

If you EVER think you might take an interest in compact Macs, go ahead and invest in a good 12" long or longer T-15 Torx driver. This is an essential tool for opening compacts, and can make life easier on other Mac repairs. Offhand, mine has helped me remove LCSs and also swap CPUs on Mac Pros.

I'll probably pick up such a tool but it's doubtful I'll pick up a compact Mac. I had a Mac Plus years ago and ended up getting rid of it as I didn't have any desire to hold on to it.

 

[Altemose]

@ITguy2016 Removing the CPUs and heat sinks (LCS) is not challenging on a G5. If the CPU cover already has had the pin broken, it will be a easy removal. Otherwise, I recommend cutting the pin out. If you want to run the G5 as is, I would keep a careful eye on the temperatures. The only issue I see with running as is, is that leaks do not seal themselves (except in rare circumstances).

 

[ITguy2016]

@ITguy2016 Removing the CPUs and heat sinks (LCS) is not challenging on a G5. If the CPU cover already has had the pin broken, it will be a easy removal. Otherwise, I recommend cutting the pin out. If you want to run the G5 as is, I would keep a careful eye on the temperatures. The only issue I see with running as is, is that leaks do not seal themselves (except in rare circumstances).

That pin seems to be a PITA...way too much trouble to remove given its purpose. I'm going to pull it out of the 2.0GHz system to see what it takes and, more importantly, to see if reinstalling it is necessary. Such a simple part yet so challenging to remove. I get the impression it is a remove and replace item instead of remove and reinstall. Aside from that removal seems pretty straightforward...so I'll likely do it.
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That pin seems to be a PITA...way too much trouble to remove given its purpose. I'm going to pull it out of the 2.0GHz system to see what it takes and, more importantly, to see if reinstalling it is necessary. Such a simple part yet so challenging to remove. I get the impression it is a remove and replace item instead of remove and reinstall. Aside from that removal seems pretty straightforward...so I'll likely do it.

Hats off to Eric Y for his direction on removing this pin. Took all of 60 seconds to pull it out using the method he provided. Now all I need is the long torx driver...which will have to wait until tomorrow.

 

[bunnspecial]

I cut the pin on the main Quad I use. The cover stays in place well enough on its own, so didn't see a pressing need to replace it.

Although not exactly a perfect replacement, you could probably use a small drywall anchor to get something functionally similar.

 

[ITguy2016]

I cut the pin on the main Quad I use. The cover stays in place well enough on its own, so didn't see a pressing need to replace it.

Although not exactly a perfect replacement, you could probably use a small drywall anchor to get something functionally similar.

I was able to quickly remove it with the screw recommendation Eric provided. It actually went pretty smooth and it's reusable (though not in perfect condition). I can see this pin being unnecessary as the cover is held firmly in place without it (I had to pry the cover apart with a screw driver).

Now the next step is to unscrew the processors. The correct tool is a #15 torx?

 

[Altemose]

Now the next step is to unscrew the processors. The correct tool is a #15 torx?

Yes. You need a long shafted driver in order to get access to screws. Make sure you lay your G5 on its side on a towel to prevent damage to the case or losing the screws in the abyss (power supply).

 

[bunnspecial]

One other thing that I rarely see mentioned-

The LCS G5s have a plastic "drip tray" under the system with a cut piece of material called "Pig Mat." This is a wonderful, amazing, super-absorbment material. We get it at work all the time as a shipping material for chemicals, but unfortunately I don't know of a good source to buy it in small quantities. I always replace it when I'm working on an LCS G5 as I often end up vacuuming most of it out when cleaning the dust, but again I don't know of a good source for small quantities.

Perhaps I should cut up some small pieces and offer it here for the cost of shipping...I need to get one apart and actually measure the correct size. I hate to brag as-since it's essentially a waste product at work-it's free to everyone for the taking. We get a LOT of it, too, a when we order a case of 4x4L glass bottle comes and each is individually wrapped in about 3 layers of the stuff. I use lots of it when working on my car to soak up oil spills and clean up oil on parts, aside from whatever other use I can dream up.

 

[Greene]

[...]
We get it at work all the time as a shipping material for chemicals, but unfortunately I don't know of a good source to buy it in small quantities.
[...]

Amazon has listings for some smaller quantities around the $20 - $40 range, although the quantities offered are still overkill for the application. I believe the Autozone caries a generic 15 x 50 roll for $20.

It's also not bad stuff to have on hand, I bought too much when I overhauled a quad and found plenty of uses for it afterwards!

 

[ITguy2016]

Yes. You need a long shafted driver in order to get access to screws. Make sure you lay your G5 on its side on a towel to prevent damage to the case or losing the screws in the abyss (power supply).

I received my long handled torx screwdriver set yesterday and I'm glad I ordered the set and not the T-15 driver. At least for the dual 2.0GHz PowerMac G5 the correct size is T-10. I haven't had an opportunity to verify if the 2.7GHz system uses the T-10 however I suspect it should.

 

[Altemose]

I received my long handled torx screwdriver set yesterday and I'm glad I ordered the set and not the T-15 driver. At least for the dual 2.0GHz PowerMac G5 the correct size is T-10. I haven't had an opportunity to verify if the 2.7GHz system uses the T-10 however I suspect it should.

The sets are almost always the better deal when it comes to buying tools.