Good source for CPU/GPU shims?

Ok, so today I got a 15" PowerBook G4 via a trade. It's the 1.67GHz DLSD/HR model, and was one of the very last ones made (January '06).

Anyways, as with all of my laptops, I pulled it apart to refresh the heatsink grease to keep things cool. However, upon removing the logic board and heatsink, I noticed that the copper heatsink pads do not touch the CPU or GPU whatsoever. Hmm.... interesting, eh?

So I did some research and found that I'm not the only one to discover this. It seems that instead of Apple finding shims to put between the CPU/GPU and heatsink (Due to a design flaw), they decided to just glop a ton of heatsink grease on them in hopes that they would be fine. It is fine for a while, but eventually the grease flows outward, making the GPU and CPU susceptible to overheating and/or failure. Luckily, mine is not one of the ones that failed, and I've caught it in time.

Saying this, does anyone have a good source for copper shims that are of various thicknesses? I plan on putting some shims in there to solve the problem. Any help is appreciated on this!

Yipe! That explains why it was running so hot...I should've thought to check that, but I guess "the CPU does not actually come in contact with the heatsink" isn't some that would ever have occurred to me... :/

Yeah, I had read it in the past which sparked my interest to pull it apart. Like I said, it's fairly obvious that Apple tried to "fix" it with huge glops of thermal compound. It will be fixed though! My 867MHz PowerBook ran hot as well, but it doesn't have the same problem... it just needed new compound.

I just wish Apple would man up and admit that they made a mistake. :lol: Were they really that cheap to not buy shims to solve the problem?

Try Home Depot or Lowes for copper flashing; any good art store usually has some; some hobby stores have some (but usually more sheet brass). There are also online places, but the shipping will kill you.

Yeah, I found a lot of them on eBay, but I don't feel like waiting a few weeks for something from China. I will go scope out the home places for flashing... I never really thought about that.

Ok, I found my feeler gauges this morning. I attached the heatsink assembly to the board and determined that the airgap between the GPU and the heatsink is exactly 0.8mm. That's good considering it's a common size for shims. The good thing is that the CPU won't need shims because it touches the heatsink when tightened down.

Found some! I ended up doing numerous searches on eBay and found a seller in NY. $1.99 for 1 0.8mm shim... free shipping. I know I could get them cheaper, but I'm not waiting 3-4 weeks for something from China.

I think Apple used a thermal pad on a lot of the G4 laptops. The pad was a thicker cushion that took up the space between the heatsink assembly and the GPU. Is it possible that someone removed the heatsink in the past and just used thermal paste on the GPU when they reassembled the laptop?

I know that the G3 Lombard's used thermal pads, but I'm not sure about the G4 as I've read that Apple did the thermal grease packing on Intel models. I don't get that though as it's common sense that once it dries out, it cakes into a hard to remove glop.

Nope, I'm not the only one to pull apart one of these models to find this from the factory. One guy on another forum pulled his apart to find the problem with his running hot, and found the same exact thing... tons of compound glopped on the CPU and GPU. And he bought his new, never cracked open.

In any case, I got the shim today, and installed it. Runs WAY WAY WAY cooler than it did. I'm happy.