Bug #1024 (oscillating re-camping), a possible solution.

[Daniel Willmann]

Hello,

On Wed, 10 Jun 2009 10:32:59 -0300
Werner Almesberger <werner at openmoko.org> wrote:

> Nils Faerber wrote:
> > For testing the process I tried to do the rework on a NEO1973 and
> > promptly got into trouble - I was not able to remove the capacitor!
> > Is it possible that it is glued to the board?
> 
> Oh, so I wasn't the only one with that luck. When I tried to
> convince Dieter that replacing the capacitor was really easy,
> I decided to give it a swift try on one of the GTA01
> pre-production units I have and then brag about it.

let me brag instead. :-)

> My first try was the "single iron, lots of solder" attack.
> To my great dismay, the cap didn't budge. I then went through
> all my electronics torture chamber has to offer, hot tweezers,
> etc., with pretty much the same lack of result. In the end, I
> reduced the problem to a simple mechanical one that could be
> solved with a dremel.

Okay, harsh measures...
I've since reworked about 6 or so (all various GTA02 versions - A5/A6,
MP and prototypes) and I managed to get the cap off on all of them. I
have to admit that it's not too easy, though.

Be aware that the right side of the cap is connected to the
groundplane, so you need quite some energy in order to get it to heat
up enough. There could also be glue in the mix, but I'm not sure how I
could check that.
I usually heat up both sides with two soldering irons wait a little and
then try to move it around a little on the board until it's loose. Then
I gently lift it off while holding it between my two soldering irons.


Regards,
Daniel Willmann
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