High temperature after thermal paste replacement

I have replaced the thermal paste on my Macbook Air 2010 and am experiencing CPU Proximity high temperatures as per MacFan Control. Macbook was running hot when I would surf the net or watch video so I decided to replace the thermal paste which I have done dozens of times to Mac's and PC's.

I used Arctic Silver 5 and also applied a thin layer over the CPU and GPU and not on the heatsink. I didn't want to apply too much since it's conductive but I noticed with the original thermal paste (by apple) on both the chips was heavily coated prior to removing it. I see the heatsink on the Macbook Air is slighltly different as its not flat and wondering if maybe there is not enough thermal paste.

Applicion method I used to apply the thermal paste was I covered the chip all with a thin layer across the entire chip but not too much to spill on to the circut since Artctic Silver 5 is conductive.

I have restarted it few times, let it run and when it loads it runs close to 95 degrees celcius on CPU Proximity but drops to around 70 degrees idling . However CPU Diode is around 65 degrees and runs between 10-40 degrees higher.

I am thinking of maybe changing Thermal Paste to non-conductive and apply a lot to cover the chips heavily with the indented heatsink on Macbook Air's.

Has anyone else experienced similar issues with new thermal paste application?

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The assemblers At the factory can be messy. You don't need to emulate the way they do things.

Thermal paste is designed to fill the micro gaps between the heat sink plate and the top surface of the chip. Bleeding over the edge is both a waste and as you know can be a problem if the compound is electrically conductive.


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Did you note any oily looking substance on the logic board around the heat sink. If so the mostly candidate for overheating is the heat sink itself, These are liquid filled and can leak, thus loosing their ability to dissipate the heat. Replacement is your only option if such is the case.

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Agreed! The coolant within the heat transfer tubes leaks out. You'll need to get a new heat sink. The new one will be a few oz heavier than yours (the missing fluid)


I am checking it now but can't see any oily substance on the logic board itself. However, there was slight white discoloration against the black heatsink surface which I cleaned. If it's a faulty heatsink is it possible to see where it is leaking after several hours of usage or does it need to reach high temperatures for the oily substance to flow out of the heat sink to pinpoint if it is faulty?


Adrian I've changed a lot of these out but never actually seen the leak. Most likely it occurs where the tube is crimped.


Rarely did I see the fluid, mostly the tube would have a visible corroision spot to white powder.

I've used a non contact thermal probe to measure the tube which was the best way without taking it out. Still it was limited. I found the weight difference was the better method.


There are many controversies as to which method is best in applying thermal paste on to the CPU & GPU. From your experience which method do you recommend? I have used the spread method and the line method but just wondering what people use that is proven with results.


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