Re: Broken heatsink - how to fix - broke.jpg (0/1)

Pedro wrote:
You can solder the hook back in place. There is no need for thermal epoxy.

The problem with the method, is the original hook, that the spring clip hooks
onto, is made from the wrong metal. It solders poorly, which is why it pulls
out of place.

If you purchase a 1/2 watt resistor, and cut the legs off it, the wire from
that can be used to make a new hook. And the tin-lead finish of the resistor
leg, solders well, and won't come out.

*******

If you really want to use thermal epoxy, it is *permanent* and cannot be removed.

http://www.newegg.com/Product/Product.aspx?Item=N82E16835100005

You mix the two components together, and apply it. Once the heatsink
sets with the epoxy in place, it can never be removed again. If you
try to remove the heatsink, it will rip the lid off the Northbridge.

Paul


I think I like this idea better than glueing the heatsink to the
chip but I have no experience at all when it comes to soldering. How
much practice would it take to get good enough at it to do a job like
this? How many ways are there to screw up? Do you know of any websites
that have tutorials demonstrating this sort of thing? It wouldn't have
to be this partuclar task, just something similar that would give me a
general idea what to do and what sort of problems I might run into.

thanks a lot for the reply

Do you have a Radio/TV repair shop close by ? They know how to solder
and do so all day long.

Pull the motherboard.

Bring the heatsink, spring clip, and the old hook with you. Ask them to make
a hook for you, out of a resistor lead or from something they know
will solder well.

You should also prepare the top of the Northbridge chip. A
rice grain sized dab of thermal paste (not glue), should be
present on the top of the chip, just before fitting the
heatsink again. That is to enhance thermal contact between
the aluminum heatsink and the top of the Northbridge. I've been
using the same tube of thermal paste for years, so a little
goes a long way. You can test whether you're using enough,
by applying half a rice grain, push the heatsink onto the
Northbridge, and see how much it spreads out. Clean the surfaces
again, with an alcohol-damped cloth, let it dry, before making the
final application. By "calibrating" the application of the thermal
paste, you're trying to ensure the paste doesn't go all over the
place. It should not be allowed to contact any resistors, capacitors
or other components.

http://www.newegg.com/Product/Product.aspx?Item=N82E16835100009

The staff at a Radio/TV shop will have soldering equipment
and can do the work.

Other than that, if you want to do the work yourself, you'd
need a soldering iron, solder wick (to clean up the work
site around where you're going to solder), some resin core
solder (not acid flux, because it can corrode things), and
practice on some other printed circuit board first.

I have a collection of (cheap) soldering irons, and for this
work, I'd probably pick my 80W iron. It all depends on how
much copper plane the hook is embedded in. Large copper
planes act as heat sinks, and prevent the solder joint from
getting to the proper temperature. I have 15W and 25W irons,
and my next size is 80W. The smaller ones probably wouldn't
get hot enough to do a good job on the hook. The Radio/TV shop
will have a soldering station with a temperature controlled
tip, and it does a better job than the cheap soldering irons
I have here at home.

It is too bad there aren't screw holes in the motherboard,
as there would be an alternative if that was the case.
But if all the motherboard comes with, is the holes for the
hooks, you have to use hooks to fix it.

Paul
.

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