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View Full Version : powerbook g4 12" gpu thermal paste or pads?




Caradog
Oct 17, 2009, 01:28 PM
Hi all,

I am putting a 12" Alum 1.5 Ghz PB back together after very reluctantly needing to take it apart (DC-In Board problem).

There is some white hardened thermal paste on the CPU which I am cleaning off with isopropyl alcohol and will be replacing with arctic silver for reattachment to the heatsink.

My problem lies with the GPU and the system controller/northbridge chip(s). They both had a blue thermal pad between them and the heatsink.

So do I

a) Remove these and put thermal paste directly on these chips instead?
b) Replace these both with new thermal pads?
c) Re-use the existing thermal pads?

I have a read an opinion elsewhere about a possible gap between the heatsink and these chips if paste is used instead of thermal pads. Should I use paste for the CPU then and pads for the other chips? Or is this nonsense?

Thanks very much in advance!:)



Hookem
Oct 19, 2009, 10:51 AM
Are you using Artic Silver 5 ??? If so I would recommend something else. Artic Silver recommends reapplication once a year. So unless you are willing to reapply every year then I would use something else.

Artic Silver Ceraminqe would be a better choice even though it does not perform quiet as well as the AS5. I have been using it and the Artic Cooling MX-2. Artic Cooling claims it will last 7 to 8 years.

On the thermal tape end of it. I would not use it. I have had some bad experiences with it besides its poor performance compared to some of the well known thermal paste on the market.

On the cleaning end of all this business. I have found using it alcohol alone does not do a very good job of prepping the surfaces for your thermal paste.

Some of OEM stuff is thick and very hard to remove with alcohol. I recommend OOPS! all purpose remover. If you let it soak in it will soften the hardened thermal paste and make it much easier to remove. Artic Silver has a 2 part cleaner but since I have gotten it not run into any of the "pink bubble gum" or thick hard white timm. So I have no idea how it works on that stuff.

I have cleaned copper heatsink with 90% alcohol to where they look spotless. Then taken OOPS! and turned Q Tips black. So in my experience alcohol alone does not do a very good job of prepping the surfaces.

So OPPS! to remove the hardened paste. Then alcohol for prepping the surfaces and Artic Silver Ceraminqe or Artic Cooling MX-2.

:apple:

Hookem
Oct 19, 2009, 11:31 AM
Also...Thin is in...You really just want enough thermal paste to cover the processor. I use a single edge razor blade to remove as much thermal paste as possible and still have completely cover the processor.

So you want both the processor and heatsink super clean and a very thin layer of thermal paste for maximun cooling performance.

:apple: