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Comprehensive Guide to Converting G5 Quad to Air Cooling
- Thread starter mac57mac57
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What difference is there between the dual pump and the single pump CPU cards? I thought only the cooler was different.
I can confirm that the actual PCB is the same between them. The only difference is the height of the integrated heat pipe / cooler assembly.
I have actually swapped out that assembly from Dual Pump cards with the larger assembly from the Single Pump cards and the result functions perfectly. I visually examined the CPU card PCBs before doing this - they ARE the same card.
I have actually swapped out that assembly from Dual Pump cards with the larger assembly from the Single Pump cards and the result functions perfectly. I visually examined the CPU card PCBs before doing this - they ARE the same card.
hi everybody! Many thanks for the comprehensive guide to the OP; this is a new concept about this subject that had been recurring many times on this forum. Reading so many interesting news about air coouling of the Quad. I approached to this (for me) very difficult modding operation myselt, in the past nobody had ever attempted to customize a PC/intel/AMD heatsink as the OP did...before everybody went the "original DC 2,3" modding way, and I followed it too. Having at my disposal only two 2,3 GHz G5 CPUs, i purchased two DC 2,3 heatsinks and modifying them with the help of a workshop I fityted the processor cards on them so as to obtain a 'FrankenQuad' 4x2,3 GHz. In the beginning all was well, temps were down an I was a happy camper with my reborn machine, but things started to crumble when suddenly I got the dreaded 'corrupted screen' @mac57mac57 is writing about in the previous posts. Currently ALL of my two CPUs are afftected by this issue, I tried to swap them and running only one or the other in the top CPU A slot....no way. I carefully verified with the help of a powerful lens if there were dents or cracks on the dies that could explain this behavior, but I saw nothing particular. I thounght that in the end maybe the 20 years old components and the die itself can have degraded with heat over time, or that the solder joints (the infamous lead free solder) can have given way somewhere. Has somebody - apart the OP- found this problem somewhere? Is there any solution?? (here in Europe these cards are a true rarity, let alone in Italy) . Thanks
Yes, exactly. heatsinks have been CNC'd and processors were fitted on them. Everything was perfectly running, very good temps also. Until one day, I fired it up and found this kind of desktop corruption you find in the enclosed photo. It's not the GPU, I replaced it with two different Geforce 6600 from other (functioning) G5s and the issue was there just the same.
Attachments
Wait, from this picture, I can only see a single 2.5GHz CPU. Are both of them installed?
I would not use a modded OS, as long as the root cause is found at least.
So first let's check if the CPU cards are socketed, and disconnect any optional add on cards. Connect only the disk that you use for the OS. Reset PRAM and NVRAM. Then run thermal calibration and the extended test in Apple Hardware Test.
Since you tried known good GPUs, I have a feeling one of your RAM sticks have failed. I have also encountered graphical glitches when using a cheap SSD with a SATA addon card in my G4, so it may even be that your hard drive is going bad and the OS is corrupted.
So if you go through all the steps and AHT doesn't report RAM issues, it may find the hard drive is failing.
If not, I'd reinstall the official Leopard and then run some tests on that, to stress the system and see how it is under load.
When does this glitch appear by the way? What do you have to do to trigger it?
Note:
My G4 MDD is picky regarding RAM, so when I was debugging it, the tests would in some cases finish and report the RAM issues only when I ran the extended test. In some cases AHT would not even load but freeze, or freeze while running the memory tests. So I recommend you take out all modules and use only one pair that you know are working and compatible, especially if you're using different modules. This way the tests will complete faster too, and you'll have time to check the rest afterwards. I have 8x2GB ECC DDR2 sticks in my Quad and the extended test took around 10 hours to finish.
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I can confirm that the G5 (Quad) can be funny about RAM. Mine came with 4GB of Non-ECC DDR2 and I wanted to see if I could upgrade it to 8GB with some of the DDR2 memory I still had around. I did eventually find a pair of 2GB modules that worked, however a bunch of others I tried would either prevent the G5 from booting, or (and I have literally never seen this before) just simply not show up at all. To make things even weirder, with the "new" RAM in certain slots, the G5 would only see some of the known working modules, presumably the ones closer to the CPU than the non-working ones.
Anyway, in case of sudden inexplicable problems with a G5 that worked before, I'd always check the RAM first as well.
Anyway, in case of sudden inexplicable problems with a G5 that worked before, I'd always check the RAM first as well.
@silentdragon95, I'd like to expand upon the "what to do when my formerly working G5 no longer does?" question.
I agree that RAM is often a culprit, but after much research, prompted by my own G5 Dual, which years ago just stopped working, and so stubbornly that I thought it was permanently bricked. I tried everything. I reseated the RAM, I reset the SMU, I unplugged it and left it sit overnight.... Nothing seemed to work. The machine stayed stubbornly quiet, refusing to spring to life.
My continued Google search for a solution eventually turned up one unexpected result, which turned out to not only work, but has solved similar problems for me many times since. Simply stated, reseat the video card. This little bit of "magic" revived my G5 Dual immediately. Expanding this thought, I would suggest reseating all PCIe cards in the slots. Perhaps there is something funky about the G5's PCIe bus that can occasionally get it into an inoperative state? I don't know, but I do know that this has solved the "non-responsive" problem for me many times over the years.
So, yes, reseat the RAM, reset the SMU, but if none of that works, reseat the video card, and perhaps all PCIe cards present.
Note that there is a little plastic tab at the front of the video card slot that catches when the card is inserted and holds it in place at the front end. The slot screws hold the other end in place. You will need to essentially break that little tab off to reseat the card. It feels wrong, but do it!
I agree that RAM is often a culprit, but after much research, prompted by my own G5 Dual, which years ago just stopped working, and so stubbornly that I thought it was permanently bricked. I tried everything. I reseated the RAM, I reset the SMU, I unplugged it and left it sit overnight.... Nothing seemed to work. The machine stayed stubbornly quiet, refusing to spring to life.
My continued Google search for a solution eventually turned up one unexpected result, which turned out to not only work, but has solved similar problems for me many times since. Simply stated, reseat the video card. This little bit of "magic" revived my G5 Dual immediately. Expanding this thought, I would suggest reseating all PCIe cards in the slots. Perhaps there is something funky about the G5's PCIe bus that can occasionally get it into an inoperative state? I don't know, but I do know that this has solved the "non-responsive" problem for me many times over the years.
So, yes, reseat the RAM, reset the SMU, but if none of that works, reseat the video card, and perhaps all PCIe cards present.
Note that there is a little plastic tab at the front of the video card slot that catches when the card is inserted and holds it in place at the front end. The slot screws hold the other end in place. You will need to essentially break that little tab off to reseat the card. It feels wrong, but do it!
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Well, @haramia, that has been my consistent experience on every late 2005 G5 I have worked on.
Yes, if you are really dextrous, you might be able to push that tab out of the way while simultaneously pulling the card out of the slot, but I couldn't do it. In the end, I just snapped off the little plastic tab and all was well.
Yes, if you are really dextrous, you might be able to push that tab out of the way while simultaneously pulling the card out of the slot, but I couldn't do it. In the end, I just snapped off the little plastic tab and all was well.
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