Comprehensive Guide to Converting G5 Quad to Air Cooling

[Doq]

And another thing: Is it not possible to use the original air coolers from the dual core models? Will they not fit?

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.

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

 

[treellama]

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.

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!

 

[b251]

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?

 

[Doq]

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.

 

[mac57mac57]

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.

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.