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LCS Issues Late 2005 Quad
- Thread starter rawweb
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The only issue you may find is having a long enough Torx screwdriver to reach the screws.
If that's the only issue it'll be a first.
Don't be pessimistic! It might work out and that could be all it is. Do you know if there's a way to disable CPU1 in a Quad?
Have you looked at the "hwprefs" command I mentioned in an earlier post?
Under the "Processor Count" command it mentions disabling a "Specific" processor.
Sorry, but this is all I can think of.
Under the "Processor Count" command it mentions disabling a "Specific" processor.
Sorry, but this is all I can think of.
From everything I'm seeing it really looks like both pumps are working nominally, my gut says it's a thermal paste application. Sadly the teardowns I'm looking at don't show any good way to get to the processor to reapply paste. I have to believe this computer sat for a long time unused and that thermal application "dried up". Why? After running it for two days the temps on processor A have come down and the margin between the two appears to be closer. It's almost running fine for a computer of it's age.
EDIT:
In fact the service manual states "Warning: The heatsink and processor are one unit. Do not attempt to separate the heatsink from the processor."
It would seem investigating this has reached a dead end.
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Yes I did and that's awesome. However, the system won't allow me to disable CPU1. No worries!
The warning is so that people don't remove the heatsink form the processor when it's still in the case. The fact that Apple put in a procedure to replace the CPUs tells me that they either expected it or considered it in the design.
If the quad is like the 2.7 LCS, you can remove the LCS/processors as a unit, then remove the processor cards and redo the paste.
Yep...theres no hope now. I fu**** it up good. I dove into it this evening with the service manual and found the removal of the processor assembly was pretty straight forward. When removing both CPU's I could tell there was definitely some thermal paste issues, cleaned it all off and reassembled. Booted into OS X and CPU A was approaching 200F, much much worse than before, however, CPU B was in the 70 degree range (I should have just ran thermal calb at this point but I apparently was delusional). Thinking I botched something with CPU A I took it back apart and cleaned it and applied new thermal paste again. Once reassembled, I got instant overtemp LED and within a few seconds a checkstop light and a complete freeze. Just finished taking the entire assembly apart again and checked very closely for damaged CPU pins on the LB, but it all looked fine. Reassembled again and still got the lights. This thing is as good as a paperweight now...I really regret tearing into this. I've definetly learned my lesson. This is the first thing in my life technologically I just couldn't seem to conquer. Bummer.
NO!!!!
Well that sucks! What if you try again but have it in a really cold area and see if ti will at least boot to ASD and run TC to see if you can get it going again?
How much paste did you use and which paste?
Here's a question, do you have to have both CPUs plugged in or can you simply just switch the CPUs and try it that way? If CPU B was fine then maybe there's s till a way to save the machine and then with the CPU A in B's slot, run TC again?
I don't know.
You're fine. Sort of... Just stop experimenting with the ASD you're not doing any good to those cards in there with temps that high idle, yeek.... But... You absolutely need a rebuild on the LCS. There are small filters in the lines and those get gummed up and won't let coolant flow. The coolant in this stuff is nasty. Checkstops and overtemp leds were my hell. The fan speeds are responding directly to your core temps. Fix the core temps and your fans will respond accordingly.
You took the LCS out and that could have shifted things and now either a pump has failed or the clog is worse. I'm thinking clogged up.
I have this exact model. Dual pump stock and everything. It's impossible to successfully rebuild it IMO. I tried it and filling it is one thing, then bleeding air out of it is a nightmare. Not to mention getting into it with all of the epoxy... and getting the lines off requires cutting. Each processor has a separate chamber which makes it harder. If you want to try and rebuild this unit, keep the existing tubing on the lower half and get a way to flush it real well. Still don't recommend tho. Junk it and keep the pumps for backups.
With mine, I bought a single pump version off ebay (others are right in that they're all lemons. Finding a good unit I don't think exists because of their age) Went through this bad pump fiasco already and had a not-so-pleasant chat via ebay for weeks. finally got refunded for a bad LCS.
I refurbished a single pump version with great success. Temps hover around 35 - 40C (95 - 100+/- F). Careful with the pump tho... they can get stuck on max rpm. The following guide has a pump refurbish as well. If that happens check out DIYINHK DDC pcbs
You rebuild that LCS, you're golden. Even if you get it to pass thermal cal your fans will still be high rpms. I can tell you need a rebuild because of the temperature disparity between CPU A and CPU B Mine had the same thing. Only the other way around. This guide: http://www.saunalahti.fi/~holindho/g5-quad-v1-lcs-repair.html is amazing and a huge help.
I have a whole bag of the special O rings for the cpu block if you end up going this route. Happy to send some your way.
Also, toss the black plastic shield thing you have around the cpu dies. Thermal paste gets in the gaps and acts like an insulator. This doesn't help your situation.
Here's some pics if you're interested: http://imgur.com/a/P8QKX AND http://imgur.com/a/3I7Cg
I spent this last summer getting one of these in prime condition. Lemme know if you have any questions
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At this point, I was able to get the seller to refund me over half the cost but I'm still out some good cash at this point. I might just part what's good like the graphics card and cut my losses while I'm ahead. Rebuilding the LCS seems too difficult a task without a guarantee of success. It's a real shame, I'm not kidding, this case doesn't have a single blemish on it. The attached pictures are right after I pulled CPU A, it did have some strange discoloring on the upper right that seemed a bit off to me. Prior to my awesome foray into removing G5 processors, CPUA was idling at about 118F while B was around 80-90F. I certainly could have chugged around with it for a while longer like that, at least it was working. Blah!
BTW, a quick check of eBay reveals some pretty slim pickings if I wanted to replace the processor unit. Anyone have any thoughts on something like this? http://www.macpalace.com/661-3729-processor-quad-630-7419-631-0204.html
BTW, a quick check of eBay reveals some pretty slim pickings if I wanted to replace the processor unit. Anyone have any thoughts on something like this? http://www.macpalace.com/661-3729-processor-quad-630-7419-631-0204.html
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As JRDN indicated however, it seems, it would be almost impossible to recharge this dual pump system without air bubbles getting in. I just don't have the necessary gear to do this job. There doesn't appear to be a definitive guide on the net to do this with the dual stage pump either. Frankly, I wish I could just take it to an auto mechanic and get a coolant flush...lol
Do you think that link I shared is worth investigating? Or would I ultimately end up with yet another junk unit?
I hate to sound like a broken record MacCubed, but how on earth do you overhaul a dual pump system? I don't have any vacuum gear to make it air tight? I wonder if my CPU A is beyond the point of repair...did you look at the shot I posted after removing the original thermal grease?
OK, heres a really dumb question in case I botched the grease job since the problems started after that....what's the best method to apply thermal paste to these. It's not at all like a traditional processor so perhaps I screwed something up. If I crack it back open tonight, should I take an earlier posters recommendation and remove that black shield surrounding the processor?
OK, heres a really dumb question in case I botched the grease job since the problems started after that....what's the best method to apply thermal paste to these. It's not at all like a traditional processor so perhaps I screwed something up. If I crack it back open tonight, should I take an earlier posters recommendation and remove that black shield surrounding the processor?
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Overhauling the pump would mean doing what the other poster did and basically redoing it. This might be a good opportunity to get newer hoses that are silicon instead of rubber if you wanted. It would also be good to clean out the pump and even change the type of coolant (using mineral oil would be great in my opinion).
And a question for you, did you also scrape off the old paste from the LCS or just just from the CPU before you reapplied it?
I would not remove the black shield because that most likely prevents any Thermal Paste from being squished onto the board which could then cause some other issues. Well that's only if you use a thermal compound that has some metal in it that could cause it to become conductive.
I would just put one nice big drop in the center of the CPU and then bet on the pressure of the contact to make the application of the thermal compound uniform.
And a question for you, did you also scrape off the old paste from the LCS or just just from the CPU before you reapplied it?
I would not remove the black shield because that most likely prevents any Thermal Paste from being squished onto the board which could then cause some other issues. Well that's only if you use a thermal compound that has some metal in it that could cause it to become conductive.
I would just put one nice big drop in the center of the CPU and then bet on the pressure of the contact to make the application of the thermal compound uniform.
Have you seen this?:
http://tenfourfox.blogspot.com/2014/04/long-life-computing-plus-quad-g5-cpu.html
There are a couple links in there for additional info on servicing the LCS.
http://tenfourfox.blogspot.com/2014/04/long-life-computing-plus-quad-g5-cpu.html
There are a couple links in there for additional info on servicing the LCS.
Yes I've read that...however in all my internet searching I have yet to find one example that details how to service the dual pump coolant system, or what tools would be needed to perform the flush.
This was linked in the earlier article:
http://www.saunalahti.fi/~holindho/g5-quad-v1-lcs-repair.html
From his pictures, it looks like they can form a bunch of goop that plugs up things.
http://www.saunalahti.fi/~holindho/g5-quad-v1-lcs-repair.html
From his pictures, it looks like they can form a bunch of goop that plugs up things.
Well, I've decided I mine as well be completely crazy since I have nothing else to loose...tore completely into the LCS tonight. Since the dual pumps don't have any kind of service ports, I had to improvise the whole way and make my own. I didn't want to dink with rebuilding all the hoses, visually, mine seem fine. I ripped off the 4 air nipples or whatever they are on the radiator and the aluminum lines running to the pumps. I used a siphon and flushed both units (both directions, reverse and normal direction) with water, automative radiator cleaner, then really hot water for over an hour. I did not see any visible chunks or anything foreign coming out. The factory drain came out a clear pinkish color. The flow coming out with the power of my make shift syphon seemed really strong. Ran to the home store and started contemplating trying to solder the holes, find some kind of rubber hose clamp, or as crazy as it sounds, rebuilding the whole unit with PEX, which is rated to 200-220F. Then I remembered PEX can't connect directly to a hot water heater, which is about the same thing as a G5 ...Really not confident on any solution I was about to give up when I walked past the loctite and JB Weld glue stand and found a JB Weld that claims "Resists shock, vibration, and extreme temperature fluctuations and withstands temperatures up to 500 degrees" and about 4,000 PSI. I'm hopeful this product is as good as it states. Not entirely confident on just that alone plugging up the holes, I decided to get some loctite silicone wrap tape which also claims a resistance of up to 500 degrees. I've got 24 hours or so to wait for the cure on the holes I epoxied on the pipes. My action plan is to recharge the units with automotive grade antifreeze/coolant from the holes on the radiator I made, then seal those...Best I could come up with being as desperate as I am...
Anyone know how much coolant is supposed to fill these? I could potentially try a syringe to refill the unit. Otherwise my plan was to make a huge mess and use the siphon to refill the unit.
Either way this turns out I want to thank everyone for their input and trying to help me come with the right course of action. This has been a huge educational endeavor and I really do appreciate having somewhere to bleed my mind into. Special thanks to RedCroissant for the manual and cheerleading.
...Really not confident on any solution I was about to give up when I walked past the loctite and JB Weld glue stand and found a JB Weld that claims "Resists shock, vibration, and extreme temperature fluctuations and withstands temperatures up to 500 degrees" and about 4,000 PSI. I'm hopeful this product is as good as it states. Not entirely confident on just that alone plugging up the holes, I decided to get some loctite silicone wrap tape which also claims a resistance of up to 500 degrees. I've got 24 hours or so to wait for the cure on the holes I epoxied on the pipes. My action plan is to recharge the units with automotive grade antifreeze/coolant from the holes on the radiator I made, then seal those...Best I could come up with being as desperate as I am...Anyone know how much coolant is supposed to fill these? I could potentially try a syringe to refill the unit. Otherwise my plan was to make a huge mess and use the siphon to refill the unit.
Either way this turns out I want to thank everyone for their input and trying to help me come with the right course of action. This has been a huge educational endeavor and I really do appreciate having somewhere to bleed my mind into. Special thanks to RedCroissant for the manual and cheerleading.