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Overheating? Not enough thermal paste.


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After a few weeks of serious suffering with the excessive heat from my new macbook, I was glad to stumble upon some forum topics referring the excessive paste problem.

 

In all the situations where thermal paste is used it's really critical to use the thinest possible layer to ensure the best possible thermal contact between two surfaces.

 

Having some experience in this field with PC's I decided to roll up my sleeves and open up my mac... What I found was truly amazing: not an excess of thermal paste but an industrial load of it, covering not only the die of the chips, but the area around them, leaking even onto the logic board.

 

After careful and proper removing of the original paste and replacing it with Arctic Silver 5 temperatures have significantly lowered, although I have no means to objectively measure them.

 

As for the discussion throtling/fan starting/paste I'd say that what causes the heat is a combination of the three... The fans do start too late, the CPU runs at maximum clock all the time and the paste issue is a real issue.

 

I feel really sad that in a product this expensive and from a company with a fine reputation like apple something like this happens... I hope that a serious fix (or fixes) come out soon...

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Well it took long enough :)

 

I really took my time, all in all maybe an hour to disassemble, clean and replace the thermal paste and reassemble the whole thing (and document the process with some photos). It's a long process and I recommend following the iFixit instructions (if possible having them open in another computer or printing them out). The Apple service manual will also do fine.

 

As for temperatures, and finding Cryptonome's kernel extension only after the "mod" I was suprised to see that they remain about 65ºC idle to 85ºC full load, and it still takes a while for my fans to kick in, but that could mean some crazed out hardware, even though the surface of the computer is significantly cooler to the touch.

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Could I ask you to post some of your photos here? Feel free to just upload them to the forum - I'm sure several people would love the extra guidance.

 

Thanks. :)

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As for temperatures, and finding Cryptonome's kernel extension only after the "mod" I was suprised to see that they remain about 65ºC idle to 85ºC full load, and it still takes a while for my fans to kick in, but that could mean some crazed out hardware, even though the surface of the computer is significantly cooler to the touch.

 

The chips should still be heating up just as much as before, for the most part. The difference you should be seeing is the surface temperatures as heat is routed correctly. The heatsink taking more heat means the top of the case should not be getting as hot. Although I have noticed a couple interesting tidbits about the fans:

 

- The turn-on temp is a fair amount higher than the turn-off temp.

- Because of this, putting the system under load will result in /lower/ surface temperatures than a light load which doesn't turn on the fans.

- The system itself simply cannot reach the temps it has been reaching before the mod because of the fans. If it gets close to 'scorching', the fans have always kicked on to bring it back down, and then turn off once CPU usage has dropped off enough.

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kolenka: I agree with you, although I was expecting that at least a slight temperature reduction would occur, as the heatpipe/heatsink system would dissipate heat to the surrounding environment more efficiently than through the logic board and surrounding air as in a system with improper thermal contact between the chips and heatsink. About the fans I've also noticed a little more activity, although not the improvement I was praying to get, which leads me to think that the sensor placed upon the heatpipe also plays a important role in turning on the fans (or should I say fan, as the left side fan is constanly running at a slow speed and doesn't seem to increase it as the right side one does).

 

Mashugly: I'd be glad to post the photos I took of the "gut" of my mac during the process, but they are not as many nor have the detail and quality of this guide I've used: http://www.ifixit.com/Guide/85.1.3.html . This guide comes complete with step by step instructions and useful highlights on some photos for things like screw and connector placing and tips/warnings on specific part removal. A really must see. I will leave these photos of the heatsink and chips as I found them when I opened my mac. (Sorry about the quality and flash reflections, but my camera is not that good and I had no time or will to set up a more adequate lighting environment to take the photos and I've reduced the size for bandwitdth and upload/download time sake). If someone feels that the photos on the guide could be complemented drop a line and I will gladly try to help.

 

post-37549-1146759745_thumb.jpg

 

post-37549-1146759778_thumb.jpg

 

post-37549-1146759814_thumb.jpg

 

Just a dumb disclaimer:

Please note that I take no responsability for any failed attempt or damage occuring during this process. If you're unfamiliar with terms like philips and torx screw, zif socket, heatsink, thermal paste and the like please restrain yourself from trying this. I believe this process does not void your warranty, as I found no 'warranty void if removed' seals, but if that really concerns you... bare the heat or return the computer for servicing. That's it, i feel like a responsible guy now. :blink:

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kolenka: I agree with you, altough I was expecting that at least a slight temperature reduction would occur, as the heatpipe/heatsink system would dissipate heat to the surrounding environment more efficiently than through the logic board and surrounding air as in a system with improper thermal contact between the chips and heatsink. About the fans I've also noticed a little more activity, altough not the improvement I was praying to get, which leads me to think that the sensor placed upon the heatpipe also plays a important role in turning on the fans (or should I say fan, as the left side fan is constanly running at a slow speed and doesn't seem to increase it as the right side one does).

 

Well, the CPU core temp is also not very accurate in my experience. The only difference I see with the thermal paste is where the heat goes. Instead of dumping it into bad places, it dumps it into not-so-bad places.

 

Why the core isn't much cooler, is probably because of the environment it is in. The case heat issues are because the heat is FORCED to radiate in ways it normally isn't designed to do. The fix reroutes this heat in the proper direction, but if the cooling system itself cannot deal with the heat any better than before (move heat faster than it is being produced), then the core temp will still remain high. I believe this is the case because all three chips are sharing a path for their heat. One chip hotter than the others can consume the ability of the heatpipe to carry heat out for the other chips, or even start to warm the other chips up a little (as an exit path that is cooler than the heatpipe when the fans are off).

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That's right, although in the situations in which I've tested the graphic card was almost idle (don't know about a way of loading it in macos).

Apple could have just split the heatsink system in two, leaving a half for the cpu alone (which I guess runs hotter than the other) and the other half for the northbridge and graphic card. This would have also allowed for independent and more efficient fan management, allowing to crank up only the fan on the hottest half of the heatsink. My guess is they used this design to make use of the two passive units in both ends of the heatpipe, altough this 'multi-direccional' flow of heat in the heatpipe can render it almost useless, as you stated.

 

But hey other than this temperature/heat/fan problem and the awful noise it's a really nice laptop (when cold enough to sit on the lap :))

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OK - this time yesterday my cpu was idling at 70 degC. A little warm. This was an average over about an hour (65 to 75).

 

So last night I got some Arctic Silver 5 and today investigated the apple-inflicted damage on the heatsinks, and whilst not as bad as some photos I've seen, it was still too thick in my experience. What I guess happened was that they specified a smaller ball of paste placed on the heatsink, but are still squishing it into place rather than spreading, and to be 'safe' are still using too much.

 

Anyhoo, doing the same stuff as yesterday I'm sitting between 45 and 55 degC. This is even with photobooth running. It I turn that off I go down to about 40-45 degC. The area above the F-keys is a lot cooler, and the underside is also much cooler. I've also heard the fans on my MBP come on, which I hadn't before.

 

Nuff said.

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So it seems this thermal paste situation has caught the eye of apple's legal department: http://www.tuaw.com/2006/05/04/macbook-pro...oblem-heats-up/

 

Man, and I was planning to fix up the heat problem after all my college finals. I guess I need to search and download as much information as I can before apple destroys everything. So I think the 20th needs to be a stop the Heat day also. lol get it... heat (from apple)?

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So all Apple needed to do was learn from computer gamer kids how to apply arctic silver #5.

 

I built a computer but first I hit the web to find out some things, and the kids were all recomending AS #5 and telling people how to aply it and how much.

 

Mostly clearcut and very informative info, but there seemed to be an unresolved debate between a little girl and a little boy about whether it best to place a small blob in the center or to spread it. Both were reporting similar results.

 

I decided to go with the small blob because it was easy to see how pre-spreading rather than letting it spread as you mount the heatsink, could cause some air to be trapped. I did the small blob and also used the stuff to prep it that comes in two bottles by the same manufacturer, cleaner and neutralizer, i think they were called, because alcohol is never 100% and can leave a residue.

 

Has anyone that is reaplying the paste decided to lap the surface of the heatsink first? Or is the surface already pretty perfect. I also lapped per the girls instructions, she was an expert at both lapping and instructing. I actually went higher than her recomended 800 grit, went all the way up to 1200 grit because I had some micromesh cloth on hand and some 6" round pollishing paper disks which have adhesive so i could stick them down on the counter surface. I made it a mirror finish and it only took about a half an hour.

 

The resutls are very very good, a big typhoon on a P4, i get a frosty 30, sometimes a little more but more suprizing sometimes a little less 29 and 28. For a hot P4 those temps are remarkable. Apple need to get on the web and find those kids, so they can hire them to show them how to build computers.

 

:)

 

kolenka: I agree with you, although I was expecting that at least a slight temperature reduction would occur, as the heatpipe/heatsink system would dissipate heat to the surrounding environment more efficiently than through the logic board and surrounding air as in a system with improper thermal contact between the chips and heatsink. About the fans I've also noticed a little more activity, although not the improvement I was praying to get, which leads me to think that the sensor placed upon the heatpipe also plays a important role in turning on the fans (or should I say fan, as the left side fan is constanly running at a slow speed and doesn't seem to increase it as the right side one does).

 

Mashugly: I'd be glad to post the photos I took of the "gut" of my mac during the process, but they are not as many nor have the detail and quality of this guide I've used: http://www.ifixit.com/Guide/85.1.3.html . This guide comes complete with step by step instructions and useful highlights on some photos for things like screw and connector placing and tips/warnings on specific part removal. A really must see. I will leave these photos of the heatsink and chips as I found them when I opened my mac. (Sorry about the quality and flash reflections, but my camera is not that good and I had no time or will to set up a more adequate lighting environment to take the photos and I've reduced the size for bandwitdth and upload/download time sake). If someone feels that the photos on the guide could be complemented drop a line and I will gladly try to help.

 

post-37549-1146759745_thumb.jpg

 

post-37549-1146759778_thumb.jpg

 

post-37549-1146759814_thumb.jpg

 

Just a dumb disclaimer:

Please note that I take no responsability for any failed attempt or damage occuring during this process. If you're unfamiliar with terms like philips and torx screw, zif socket, heatsink, thermal paste and the like please restrain yourself from trying this. I believe this process does not void your warranty, as I found no 'warranty void if removed' seals, but if that really concerns you... bare the heat or return the computer for servicing. That's it, i feel like a responsible guy now. ;)

Good grief that's outragious. They must have thought you were supposed to use a whole tube on each cpu. That cleaner or solvent packaged by the same people that make artic silver is the perfect stuff for cleaning up that mess, after you carefully remove as much as possible.

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Good grief that's outragious. They must have thought you were supposed to use a whole tube on each cpu. That cleaner or solvent packaged by the same people that make artic silver is the perfect stuff for cleaning up that mess, after you carefully remove as much as possible.

 

From the MacBookPro service manual:

 

"Put a 0.2 - 0.3cc daub of thermal grease, in the center, on all three chip mating surfaces, as shown below.

NOTE: One syringe of the thermal grease (922-7144) contains about 0.2 - 0.3 cc. So use one syringe per pad."

 

Rediculus.

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ok, reopened the thing and this time i did it properly. seems pretty cool right now. started about 40 mins ago and the idle temp is 48 degrees (was 58-60), but, again, this depends A LOT on ambient temperature.

 

will observe and inform

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