Processor removal help: G5 liquid cooled

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Processor removal help: G5 liquid cooled

I am looking for some help on removing the heat sync/ processor on a dual 2.5 with the liquid cooled unit.

The 8 CPU Heatsink Allen screws 2.5 mm. that sit in the "Lagshields" are loosened, but the CPU unit still is being held down by more fasteners?

Which other fasteners ( the torx screws?) need loosening to be able to lift the CPU unit free of the board ?

Has anybody done this that can remember the procedure.

Any help is appreciated !! -john

G5 dual 2.5, processor removal

Posted on Apr 14, 2008 12:00 PM

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Answer 1

Apr 14, 2008 2:27 PM in response to johngucsb

I just bought a liquid-cooled DP2.5GHz with a presumed bad logic board. I'm about to remove the CPUs and wonder if you found any guides that helped. I have replaced DP1.8GHz CPUs but I am leery about the whole liquid-cooled thing. Do you have to disconnect any of the liquid cooling hoses? Concerning your posted queston-- I have something that might answer your question. Thanks

<post edited by Host>

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Answer 2

johngucsb Author

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Apr 14, 2008 3:34 PM in response to Toolshed4

So far I have yet to find any definitive info, though this post:

http://discussions.apple.com/thread.jspa?threadID=1434166&tstart=75

has some helpful info AND one of the people who replied to the post indicates that there is in fact an Apple Service guide (in pdf format) that pertains to the liquid cooled models though I cannot seem to find it ! This is the document that will Hopefully make life easier and help avoid doing any damage to the heat sink cooling unit while removing it.

Service Source
© 2005 Apple Computer, Inc. All rights reserved.
Power Mac G5
Power Mac G5, Power Mac G5 (June 2004), Power Mac G5 (Early 2005)
Updated: 27 May 2005

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Answer 3

Apr 14, 2008 5:53 PM in response to johngucsb

Yes, the service manuals do exist, but there's a reason they're difficult to find - they're intended for service professionals, not end users, so they're only given to Apple service shops. If you look hard enough, you can find them on the internet, though.

eBay also sometimes has them for sale.

Message was edited by: Steve Boultbee

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Answer 4

pheidius

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Apr 14, 2008 11:56 PM in response to Steve Boultbee

I have the service manual to this model.Removal of the dual cpu module is a breeze. You have to have the exact right length of screwdriver extension to loosen but not remove the 4 hold down bolts. Then you pull it straight out. but then what do you do with it once its out. The service manual clearly sys you cannot lay it on its side. The techs must have some kind of caddy to drop it in so that the pins are not broken and the water cooling seals are not stressed. Yes, it is one big unit.The scary part is getting such a big unit back in to the board with out bending pins. Then comes the really difficult part: motherboard removal. That looks ike a major pain. I can see several ways to f up putting a new one in. Why are you trying to pull the board again? Plus you will still have to take it in to the Apple store for thermal recalibration.

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Answer 5

Samsara

Level 4

1,327 points

Apr 15, 2008 4:51 AM in response to Steve Boultbee

I found my copy of the service manual on Apple's website some time ago. I haven't been able to find it again since. Not because I believe it's not there anymore, but because Apple's website generally stinks when it comes to organizing and dispensing information. And slow to boot, even with a fast connection.
Or maybe it really isn't there anymore because they make more money when Apple does the work. Apple used to care more about their end users. Apple users have always been tinkerers and Apple was always right there to help. They and their customers had to cooperate, it was a small us versus a large them. Times have changed.

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Answer 6

johngucsb Author

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Apr 15, 2008 11:30 AM in response to Samsara

Thanks to all who provided help on this. I did in the end get a copy of the Service Source for the model I was working on (a late 2004 2.5 dual LCS Heat Sink model) which made all the difference. This document is essential. Thanks to a discussion user who had a copy! In my case I needed to replace a blown PSU (not an overly difficult task for anyone who is proficient in removing and replacing components)

While I understand the logic for Apple to not make this document too readily available I disagree with this strategy. There is nothing overly technical in this document and in the end people will be lead down the wrong pathe (and do more damage) if they cannot get good info. In my case I found all kinds of miss-leading info about how to pull the processor unit for my machine. Some said remove all the screws, others said just 4 screws (in fact there are 8) Some said don't do it it is complicated, others said it is no more difficult than an air cooled unit. Oddly Apple's site only showed the Service Source document for the earlier air cooled models, which is only helpful to a certain degree.

My point is that too keep things a mystery by not allowing good info to be had causes more harm. Maybe that's the intention ? Anyway I am big fan of Open Source, collaborative sharing of ideas etc. So forums like this are a big help.

Thanks again to all !!

-john

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Answer 7

Samsara

Level 4

1,327 points

Apr 15, 2008 3:21 PM in response to johngucsb

Amen. Great work, John. 🙂

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Answer 8

highjnx

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May 20, 2008 2:27 PM in response to johngucsb

Hi John,

I was wondering if there is a way to get a copy of your user manual? I'm in a similar situation, doing a full case swap out on my older G5 2.5GHz, and ran across your thread.

As to the Service Manuals disappearing on the Apple Site - I understand that the Apple legal team is responsible for the removal of any documentation that goes beyond basic upgrades. A sign of the "CYA" times we live in as we recruit PC users over to Macs.

Any help would be greatly appreciated.

Todd

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Answer 9

Jun 15, 2008 2:35 PM in response to johngucsb

John,

I may be doing this myself on a liquid cooled 2.5 if I can confirm the psu is my problem, and was wondering if you could email me more info on how you did it, and where I can find the service manual.

Thank you.

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Answer 10

Jul 21, 2008 9:19 PM in response to johngucsb

Hi John. I too have to remove the processors and got stuck. Are you able to email me that Service manual please? I agree that it shouldn't be so hard to get the appropriate help for those of us who want to do our own servicing - to a point anyway! Thanks, Phil

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Answer 11

Samsara

Level 4

1,327 points

Jul 22, 2008 6:35 AM in response to Hatethatcat

There may be information on this page that you'll find useful
http://discussions.apple.com/thread.jspa?threadID=1434166&tstart=75

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Answer 12

Samsara

Level 4

1,327 points

Jul 22, 2008 6:48 AM in response to Hatethatcat

But this may be of help in the meantime:

The processor in this procedure is secured by four screws requiring either a long-
handled Phillips screwdriver or a long-handled 2.5 mm hex wrench, depending on the
model. To determine which tool to use, check the head of the screw in the unit you are
repairing.
If the processor mounting screws have a Phillips head, remove the four screws.

If the processor mounting screws have a hex head, loosen the four screws but do not
remove them from their standoffs.
Lift the heatsink and processor straight up out of the computer.

Warning: The heatsink and processor are a unit. Never separate the heatsink from the
processor, or you will damage the processor and void the warranty.

Note: If you have trouble removing the original processor (processor feels stuck) or installing
the replacement processor, check for damaged split standoffs. One or more may be spread
too far open, keeping the processor from fully seating in its connector. Replace any damaged
split standoffs with the standoffs included with the processor.

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Answer 13

Samsara

Level 4

1,327 points

Jul 22, 2008 7:02 AM in response to Hatethatcat

Sorry I think only some of that pertained to your specific Mac. There's this for yours:

Tilt the processor inlet frame to the left and then up to unlatch the plastic piece from the
heatsink.
Note: The processor in this procedure is secured by eight screws requiring a long-handled
2.5 mm hex wrench.
Loosen the four hex screws.Loosen the four remaining hex screws but do not remove them from their standoffs.
Hold the heatsink by the middle and lift the heatsink straight up out of the computer.
Warning: The heatsink and processor are one unit. Do not attempt to open or service the liquid
cooling system. Opening the liquid cooling system may damage your equipment and such
damage may not be covered by the limited warranty on your computer.

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