How do I replace heat sink with both thermal paste and pads?

I am reassembling my powerbook after replacing the display inverter. I want to put the heat sink back on the processor (and other chips as well below it?), but the thermal paste guide pictures and my situation look different. It appears that any paste is a bit more like a pad than I thought, though the stuff on the processor is likely some thick colored paste.

My main concern is with the pads: The pads seem about one or two millimeters thick. Would removing the pad and applying thermal paste lead to a gap and therefore a problem with cooling? If I end up reusing the pads afterall, would I then have to put thermal paste on the underside of the pad? Are there any issues with small irregularities in the pads' surface smoothness? What if the pads got a little bit of dust on them, probably during dis-assembly of the laptop? Does this present an issue? If so, would it be best to just get replacement pads or use thermal paste? Thanks for your time and effort answering my question.

Answered! View the answer I have this problem too

Is this a good question?

Score 0

Comments:

It's best if you replace thermal pads with thermal pads and paste with paste.

However, there is one thermal paste that can replace thermal pads at the moment and it is the only commercially available paste that does that (at least as far as I know). It's name is K5-PRO. It is the one I use for my laptops too.

Also, did you try to use thermal pads together with a piece of copper? It can drop the temperatures of your pc dramatically.

Anyway here is a link with thermal pad replacement using K5-PRO if you have trouble while replacing your pads

https://www.youtube.com/watch?v=JgrEyd93...

Hope this helped

by

Add a comment

11 Answers

Chosen Solution

Personally I'd dump the pads, apply the paste and seat the heat sink. Then remove the heat sink and inspect the paste to see how well contact is being made, then make my decision. If your book looks different than the guide it may be the wrong one. Please give the last three letters of your serial number to insure we're talking about the same machine. PowerBook G4 Aluminum 12" 1-1.5 GHz Heat Sink Replacement

Was this answer helpful?

Score 5

Comments:

Thanks so much for replying. It is the correct guide - I am pretty sure because I think those are the specs, and I disassembled it all the way to the display inverter without any differences in laptop design. (Serial numbers are scratched too much to read, unfortunately.) Everything in the powerbook guide looks the same, but the thermal paste guide looks like it is different: the paste looks less thick and is gray around the processor, whereas my thermal paste is a quite-thick lime green that doesn't even seem present (maybe just a very thin layer?) on top of the central metal part of the processor sticking out. The blue rubbery pads are on the underside of the heat sink (not shown in the g4 guide) and must be for the chips on the logic board below the processor. Should I try ripping off the thermal pads on the chips below the processor and trying it with thermal paste there? What if it doesn't work? Can I reapply the thermal pads or get new ones? Thanks so much for your time.

by

If al;l the thermal paste squeezed out from between the contacting parts, then a pad is to thick. I'd try the paste first and see just how much contact it's making before going to the pads. I would also not reuse pads, here's where to get some: http://www.radioshack.com/product/index....

by

I got those thermal pads, but they are very thin and incredibly difficult to apply. Not at all like the thicker, blue thermal pads that came with the powerbook. Have you ever used those thermal pads? Do you know where I could find some thicker ones? What should I be looking for?

by

Sorry, I've never used the pads or needed to, check the seating to make sure it's down all the way. There are not separate guides for applying thermal paste. That guide just shows you how to do it. Have you tried just putting paste on and seating the board to see how much contact you're getting?

by

I had to reread the whole thing to see where you did just try the paste. This still leads me to believe that it's not getting seated all the way down.

by

Show 1 more comment

Add a comment
This answer was originally to another question.

I've never used the pads. The Arctic Silver is the best paste I know of and I've never had to replace it. I'm surprised you would know of it, usually only professionals know.

Was this answer helpful?

Score 4

Comments:

Thats what I use also. +

by

Arctic Silver 5 is the most popular brand amongst them all.

by

Thanks for the replies, but my question was more along the specific tolerances of this model.

Thermal pads are pretty thick compared to a layer of compound and so my worry is that the heatsink may have a gap. So wanted to know if anyone has experience using a thermal compound in this particular case.

Once the parts arrive and I can give it a chance I'll post my findings here.

by

Add a comment
This answer was originally to another question.

Thermal paste would be better than pads. All the paste/pad does is fill in area's where the cpu/gpu and heatsink don't touch (usually very very small), ideally you want full metal to metal contact, but that's next to impossible. I would ditch the pads and get some Artic Silver 5, you should notice a few degree drop in temps

Was this answer helpful?

Score 2

Comments:

I disagree. For one, thermal pads are made of slightly different materials designed to evenly distribute heat throughout the medium while being flexible. Paste is designed to be spread as thin as possible to mate two components by setting to a hard seal. Secondly, this model has about a 2mm gap. I'm not sure how paste would compare to a pad at a given thickness, but to bridge the gap you'd end up with a goopy mess of paste that would potentially ooze out onto additional components spreading heat to them. While setting it could develop air bubbles within or after setting could even completely separate from components due to flexion of the computer during use. YMMV.

by

+ sometimes they just don't listen

by

Add a comment
This answer was originally to another question.

I faced this very issue last month when upgrading the CPU in my Compaq notebook (AMD P320 2.1 GHz dual core to AMD N620 2.8 GHz dual core). After the upgrade, I powered on the notebook, and within a couple of minutes it just shut itself right off. I did this a couple more times. Thinking it was a dead CPU, I tore down the laptop again, and discovered that there was about a 1mm air gap between the GPU and the heatsink.

When I did the upgrade, I removed the old GPU thermal pad that was stuck to the heatsink, and rather cavalierly applied Arctic Silver 5, thinking that would do it.

Well, after this epic fail, I could see that the AS5 wasn't enough to bridge the ~1mm gap between the top of the GPU and the copper heat sink surface, so I improvised: I made a heat-conducting shim.

Using a sharp knife, I cut a nice, smooth, flat 3/8" x 7/16" rectangular piece of aluminum off a thick foil casserole baking pan (about 1mm thick) that I had lying around. I cleaned both sides of the the shim with 91% isopropyl alcohol, applied thin, even films of Arctic Silver 5 to it and the heat sink ("staining" it), and to the top surfaces of the GPU & CPU. I reassembled my notebook, powered it on, and I'm good to go.

Temps on the GPU & CPU get no higher than 67°C at 2.8 GHz fully loaded, gaming, etc., which is going to be typical for this class CPU, and in a laptop. 28% speed improvement, all around. Totally worth the effort. But anyway, yeah...maybe try this aluminum shim approach. Or maybe even copper, if you can find it. Even though copper is about 3 times better than aluminum at conducting heat, I don't think the operating temperatures would be drastically lower with it.

bump

Was this answer helpful?

Score 2
Add a comment
This answer was originally to another question.

I'd also really enjoy hearing the answer to this one. The pads seem about one or two millimeters thick. If I end up just using the pads, would I then have to put thermal paste on the underside of the pad? Are there any issues with small irregularities in the pads' surface smoothness? What if the pads got a little bit of dust on them, probably during dis-assembly of the laptop? Does this present an issue? If so, would it be best to just get replacement pads or use thermal paste? Thank for your answer.

Was this answer helpful?

Score 1

Comments:

KarlD looks like this question wont get resolved since it is already 6month old. Try to ask you own question on here, It is simple and I am certain that you will get help with your question. Good luck

by

Add a comment
This answer was originally to another question.

I apologize for not updating to "post my findings here" as I promised. The gap was simply too far from the motherboard without enough pressure to make a thin layer of arctic silver a viable option. As for when you may need to replace the pads, the official recommendation is to replace the pads only if they are damaged (perhaps by removal). I specifically replaced the pads in this computer because it had overheated and I had to separate the heat pipe to replace the fans and wanted to rule out the pads too.

Was this answer helpful?

Score 1
Add a comment
This answer was originally to another question.

Errol, thanks for replying. What kind of thermal pads did you use? I tried to replace them using ones recommended here: How do I replace heat sink with both thermal paste and pads?. But they were too skinny and very difficult to apply. I doubt it will do much good. In doing so, I removed the pads, partially ripping one (and the other has dust on one of the sides). Maybe I could clean the dust off as best as possible and re-stick both on? If anybody knows what kind of pads would offer nice, thick, sticky surfaces and would be easy to apply, please let me know.

Was this answer helpful?

Score 1

Comments:

I used Apple specific kit 076-1055 ordered directly from Apple (I'm an ACMT at a Univeristy).

You can get it about $20 from https://www.applecomponents.com/items/07...

I'd definitely suggest replacing the pads if they're torn or dirty.

by

Add a comment

You can replace thermal pads with apropriate thermal paste which is designed to replace thermal pads. Normal thermal pastes should be of high viscocity in order to cover only the very small gaps between the CPU (or other hot component) and the heat sink so there should be in no way as thermal pad replacement. A thermal paste that is designed to replace thermal pads should be very gummy in order to cover big gaps and of very high thermal conductivity. There is one called K5-PRO which is designed for iMac computers but should be fine for any other computer. You can find videos of it on youtube

http://www.youtube.com/watch?v=e9v5MDivZ...

and it is avaliable on ebay

http://www.ebay.com/itm/261419411897

Just search for

k5-pro thermal paste

Was this answer helpful?

Score 0
Add a comment
This answer was originally to another question.

It's a long time since you posted this question but the problem is still around for many users so my reply can be usefull for some people. You should replace thermal pads with new thermal pads or with a thermal paste that is specially designed to replace thermal pads. Do not reuse old pads and do not replace pads with normal thermal paste like Arctic Silver. Both will lead to overheating and result to GPU or other BGA failure.

You can find apropriate thermal pads on Amazon or ebay. You should know how thik they are, how soft they are and how big they are before you order them.

Until now I have found only one thermal paste that can replace thermal pads. It is called K5-PRO and you can find videos of it on youtube

http://www.youtube.com/watch?v=e9v5MDivZ...

and it is avaliable on ebay

http://www.ebay.com/itm/261419411897

Was this answer helpful?

Score 0
Add a comment

One place that I have found nice thermal pads is on [http://www.frozencpu.com.

They have some there made by Fujipoly that can conduct 17w/mk.

I have just placed an order for 2 different sets myself and will write my findings when they arrive and I install them on the laptop I have been working on.

Student of LIT :)

Was this answer helpful?

Score 0
Add a comment

do[nt use thermal pads use thin aluminum or copper shims with paste to fill in larder gaps where pads used to be ive get 10-20 degrees cooler

Was this answer helpful?

Score 0
Add a comment

Add your answer

KarlD will be eternally grateful.
View Statistics:

Past 24 Hours: 0

Past 7 Days: 3

Past 30 Days: 53

All Time: 17,348