Need to replace CPU heatsink and fan

Now that my old A7V8X is up and running again I need to address an
issue that is long overdue. The CPU fan is loud, I mean really loud. I
need to replace the fan but I assume that I will have to replace the
heat sink too.

How much of a problem is this going to be. Will the old heat sink be
glued to the CPU by heat sink grease or some other form of attachment
that has been baking for the last three years? What is the best way to
remove it without trashing the CPU?

Also, I'd like to get some quieter case fans, preferably ones that
adjust their speed based on the case temperature. I recall that Fred
Langa was discussing these fans a year or so back.

Any suggestions?

 

Visit electronic supply houses such as Allied Electronics,
Newark, Jamesco, Digikey, or Mouser. Notice all the fans of
same size and voltage have numerous other parameters such as
noise and CFM. All sources available on-line.

 

For removal, the only suggestion I've seen, that makes intuitive
sense, is to run the motherboard for a few minutes, to warm up
the CPU and the heatsink. The thinking is, this will make the
dried thermal grease/paste a bit more pliant. A ten minute run
should be enough, followed by shutdown, unplug, and an immediate
attempt to remove it. But the assembly will cool so quickly,
maybe this really doesn't help...

It is a tough call, as to the best method of removal. You'll find
enough tales, about pulling on the assembly, and yanking the whole
thing right out of the still-closed socket. I don't know of a totally
risk free way to break the fit between the grease and the silicon
die. Anything I suggest, could still damage it. Twisting the heatsink
is one possibility, and that applies a more uniform force to the
face of the die, than perhaps a rocking motion. But the material
scraped off by the edge of the die, implies there is still a
possibility for some damage at the edge. A rocking motion, or putting
pressure on one side of the heatsink, might chip the edge of the die.

If the interface material was phase change, and not grease, it
would be a different problem again. I might just try pulling
straight up on that, because I don't know how hard the phase
change stuff gets when it is cold. Twisting against a solid
interface material sounds much more dangerous.

Depending on the design, some fans have screws that hold the
fan in place. The screws fit between the fins of the heatsink.
You can remove the screws, and replace the fan, without pulling
the whole thing. In some cases, there is a frame around the
heatsink and fan, which might make in-place removal of the
fan impossible. The only risk I see with in-place repair,
is the possibility of scraping some aluminum flakes off the
heatsink, when reinstalling the screws. The screws are self-tapping,
and there are no machined threads on the heatsink in that
case.

Good luck,
Paul

 

yes, don't pull the heat sink off the chip. all the cpu fans I've had
are attached by screws. if you can take out the screws and remove the
fan this is a much lower risk approach than prying a working chip free
from its heat sink (which works ok, right?). Then replace the fan only.
baking the cpu is an expensive mistake

d

 

Is there a standard fan size for the socket-A fans? I would have no
problem leaving the heat sink in place if I could find a replacement
fan.

 

Your answer was already provided: Allied Electronics, Newark
Electronics, Jamesco, Digikey, or Mouser. Furthermore, they
provide links to actual fan manufacturers who will have an
even larger inventory described in their web sites. The fan
industry uses standard dimensions.