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Comprehensive Guide to Converting G5 Quad to Air Cooling

b251 said:
And another thing: Is it not possible to use the original air coolers from the dual core models? Will they not fit?
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Not as is-- the dual-core cooler actually hangs over where the second processor goes so trying to fit two of them in won't work without slicing off the overhang.

Here's a thread about doing that.

forums.macrumors.com

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 forums.macrumors.com
 
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Thanks for much for this guide. I ended up buying a quad G5 for cheap (thinking it was one of the air-cooled DC models, since the seller assured me the power input was the same as the other G5), and after getting a C19 cable, it would overtemp and checkstop partway to booting from DVD.

So I got the parts in the guide and did the replacement. First start up, instant overtemp and checkstop. Went back in, tightened the heatsinks down more. Now the CPU cores idle in the high 20's, hitting 75°C or so if I really push it with Altivec Fractal Carbon.

A couple notes where I differed from the guide. For mounting the fans to the coolers, instead of duct tape, I attached the fan brackets on the top and bottom instead of the sides. I put a zip tie loop around each, pushed the bottom one under between the heat pipes, pulled them tight toward the back, and held them with a third zip tie. You need to wear a ring of dexterity when doing this, but the result feels more durable than duct tape to me. Obviously get the brightest neon colors you can.

IMG_0323.JPEG


Then to get the Molex cable from the DVD-ROM, you don't need a long pliers if you follow the directions in the service manual: remove the IDE cable from the motherboard, open the DVD-ROM levers, push up and out from the back, and when it's partway out, you can just pull the Molex cable off.

I'm really pumped to have a G5 quad now! I had been avoiding them because of the LCS. So thanks again!
 
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Giving the fact that I will entirely disassemble the G5 to transplant the components to a new housing, would this make it possible to mount the fans in the intended way?
 
Probably not. The clips on the inside (between the coolers) push on the assemblies too much, resulting in either inadequate cooler contact, or one of the processors releasing from its socket.

So unless your logic board has wider than stock spacing, you're probably not going to be able to make that work, at least in the way that both my guide and @mac57mac57's documentation lay it out.

That said, you might be able to if you rotate one of the coolers 180 degrees, which would stagger the heatsinks themselves probably enough to get the sets of clips installed. I would have probably done this had I thought of it sooner.
 
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treellama said:
A couple notes where I differed from the guide. For mounting the fans to the coolers, instead of duct tape, I attached the fan brackets on the top and bottom instead of the sides. I put a zip tie loop around each, pushed the bottom one under between the heat pipes, pulled them tight toward the back, and held them with a third zip tie. You need to wear a ring of dexterity when doing this, but the result feels more durable than duct tape to me.
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THIS is a great idea! The duct tape had the utility of simplicity, but your approach achieves a higher degree of durability. Well done!

On the topic of durability, one other thing, and I think I have @Doq to thank for this idea, but no matter what you do, the result is not as sturdy as Apple's original design. So, if you plan to move your G5 "Air Quad" from one physical location to another, and you need to box it up before moving it, do yourself (and your G5) a favor: cut up some Styrofoam into appropriately sized blocks and insert those blocks in amongst the new fans and coolers to physically stabilize them against the sort of mechanical shock that might occur if the box is dropped, or simply put down on the floor rather firmly.
 
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@mac57mac57 I'm now about to order the necessary parts. Which size of washers i should order to correspondent to the ones you used? So when the diameter of the pegs is M3.5 i assume that M4 would be the best size?

And are the CPU cards really safe in place although they are not screwed down anymore?
 
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I attempted to do the conversion and unfortunately I broke the die on its edges. I haven’t tested it yet as the knurls do not screw in anymore after they are screwed out one time and I had to order new screws which will arrive tomorrow, but I haven’t any hope that this will work.

IMG_8908.jpeg
 
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Because of the exact manner in which the corners have been broken, and as a person who has very little experience with chipped dies, I would maybe give it a non-zero (albeit still extremely low) chance of working.

The actual functional stuff, the microbumps, metallization layers and transistors constitute a very, very thin layer on the bottom of the die. The bulk of the material on the top, which is in contact with the heatsink, is more for mechanical and thermal stability than for functional purposes. I can't see very well whether the chippage on the right corner has reached the very bottom layer of the die. If it has, she's dead, Jim. If it hasn't, there's that extremely low chance that it'll boot.

If it does boot, it probably won't work for too long, because the heat dissipation ability of the affected areas will probably be impacted in a very bad way.

Yeah, all around, not a good thing. Sorry, man 😢
 
Congratulations!
Goodthat your CPUs working. I had G3 750FX, which worked many years with broken die edges and I hope that yours will be too.

I'm glad it worked out for someone else. I have the components ready and I'm still deciding whether to replace cooling...
 
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Yeah, I can confirm from personal experience that a chipped edge does not always mean a death sentence for a CPU. My 1st PC which was also a Pentium 3 has had a chipped edge on the CPU die for literally decades now and still works (yes, I still have it).
 
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I cannot find those FROZN A400's anywhere. I repasted my G5 Quad last weekend and although it did lower the temps, the least bit of activity sent the fans and single pump to the moon! Failed thermal calibration on both CPUs. Strangely, the system would idle in the low 40s and max out around 75, although the fans would be maxed and running wild. I suspect it was throttling itself too. No errors or crashing, but the noise was unbearable. I shut it down after work today and decided to dig in.

Anyhow, I removed the LCS again and drained the original 20-year-old coolant. There was very little left. It was the green stuff that smelled just like car antifreeze. I did see some signs of light coolant seepage around the single pump. Probably seeped out slowly over the years and evaporated. Fortunately, there was no damage to either CPU card or the Motherboard. I think I'm done with the LCS.

Any ideas on a drop in alternative to the A400's? I don't have a grinder for the Thermalright Assassin, but of course it is Murphy's Law the A400's would be EOL and discontinued everywhere.
 
travsG5 said:
cannot find those FROZN A400's anywhere
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Wow! I thought I would find them for sure on eBay, but no joy! I checked a half dozen places, but they are out of stock everywhere.

As you look for replacements, remember that it is more than just the physical fit. Whatever you buy must be able to dissipate the right amount of heat in addition to simply fitting into the box.

Although it is an infinitely trickier thing to do, I have had good luck with rebuilding the Liquid Cooling System (LCS).

I will keep looking for the A400s, or an equivalent, and will post back if I am successful.
 
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My understanding is, FROZN just ships your generic rebranded Chinese coolers. About half a year ago, I looked at the overall options for the for the coolers of around A400's specific width, and found two or three models which were the exact heatsink and fan, just rebranded for a different manufacturer. You might still be able to find those.

There were also different options with the same nominal heat dissipation value, although I remember having doubts about their actual ability to dissipate the amount of heat they're purportedly designed to. Mainly since, if memory serves me right, they had less heatpipes than the A400.
 
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Yeah it is a tough search, but thank you kindly for searching! I went ahead and ordered the thermalright assassins and the knurled nuts that were suggested along with some 20mm m3 bolts and washers. We know this setup at least works well from another member's experience.

Sadly, it is the single LCS pump that is ever so slowly leaking and I cannot find a replacement for it. I don't want to worry with leaks it in the future, so I'm going air. I will save the parts just in case though!

Maybe I can have my mechanic grind the heatsink fins down on the assassins as it sounds like I will need to. Gonna have to find a way!!!
 
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You should realistically be able to get away with any 92mm cooler without modifying the cooler itself, though depending on which you choose you may have to source (or custom fabricate) additional hardware for mounting.

Unfortunately, PCPartPicker is not helpful for this as while they have filters for cooler height, they do not for cooler width or fan size (which I think is a miss).
 
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Looks like Amazon Japan has the Frozn A400s:

us.amazon.com

ID-COOLING FROZN A400 Black - 4.9" Height Black Air CPU Cooler, 4×Ф6mm Heatpipes, 92x92x25mm PWM Fan, TDP 180W, All Black Layout, Intel LGA1700/1851/1200/115X; AMD AM4/AM5 (123mm in Height)

FROZN A400 BLACK
us.amazon.com

Hoping the supply doesn't completely dry up as I was looking to tackle this project this summer.
mac57mac57 said:
Wow! I thought I would find them for sure on eBay, but no joy! I checked a half dozen places, but they are out of stock everywhere.

As you look for replacements, remember that it is more than just the physical fit. Whatever you buy must be able to dissipate the right amount of heat in addition to simply fitting into the box.

Although it is an infinitely trickier thing to do, I have had good luck with rebuilding the Liquid Cooling System (LCS).

I will keep looking for the A400s, or an equivalent, and will post back if I am successful.
Click to expand...
 
silentdragon95 said:
I would just like to point out that a dremel would probably be an even better tool to do this, just in case you happen to have one. It's just that I don't, so I had to improvise.
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And it is done with the thermalright assassins. A little Dremel work on one of the heatsink side fins and it slid right in! ***note those little fins that fly off during the Dremel job are razor sharp and as hot as the surface of the sun! I wore safety glasses; I recommend anyone else does too! ***

Temps at idle are in the 35-38c range. Temps at full sustained load for one hour at 100% is 63-68c on both cpus. I guess that is working right then? No errors and the quad does seems quite snappier now! I'm pretty sure it was throttling itself before.

Thank you for the guide and also the tip about using the thermalright assassin as a replacement l! I think my Quad will live on now!
 
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joevt said:
Pictures?
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If you look where I slipped with the dremel on the lower part of the upper heatsink, that and the other side of the protruding side fins are what I needed to cut away. To anyone doing this, order a cheap set of nylon washers on Amazon of various sizes. These will help you get the height of the CPU mounting brackets "just" right and save you a lot of aggravation.

Also, I just realized I forgot to remove the dusty absorbent pad this machine doesn't need any longer.

Lastly, although it runs cool, the Thermalright fans are not the quietest things. They are not obnoxious by any means, but when this Quad was in its prime back in the day, it was near silent with the single pump LCS. I may try changing those Thermalright fans out for something else. I will clean up the wiring and remove that pad too then.
2444.jpg
 
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Glad to hear that everything worked out! I think the issue with the fans is mostly the fact that they run at 12V continuously, but there are fan voltage adapter cables that basically have a resistor built in and drop the voltage from 12V to something like 7V (they used to come with Noctua fans, but I'm sure cheaper non-branded alternatives exist as well). One would need to try how this affects the temperatures under sustained load though.

I guess the ideal solution would be to create some sort of adapter cable from the actual LCS cable harness, but that would be quite the project 😅
 
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I'm no expert on the G5 but I currently have a 2.3GHz DC (late 05) and EveryMac lists the CPU as being on a daughter card? Is possible to swap it to a Quad by simply changing the daughter card or adding in a second G5 DC?
 
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