On Sat, 14 Jun 2008 23:29:29 -0700, Jeff Liebermann wrote:

On Sun, 15 Jun 2008 12:53:59 +0800, rebel wrote:

On Sat, 14 Jun 2008 16:49:48 -0700, Jeff Liebermann wrote:

(snip)

Glue it while it's open.

(snip rest)

The most important bit of all. The solder joint should NOT be expected to
provide the mechanical support for the receptacle - only the electrical bond.

Baloney. Every single laptop I've repaired or inspected, has the
solder leads and circuit board provide the only means of support. A
few provide added protection in the form of a metal cover shield, such
as the HP laptop in the photo:
http://802.11junk.com/jeffl/pics/HP-laptop/slides/Fried_power_plug.html
I just ordered some connectors for a Compaq 1692 that also has a metal
shield. The shield helps, but is not that common.

The most disgusting was some ancient laptop, that used a surface mount
power connector with no holes through the board. The other connectors
were attached the same way. They died in a few weeks, or when the
owner tweaked the cords, whichever came first.

I think we're on the same side, but seeing things from a differnt point of view.

Certainly the manufacturers rely only on the solder to provide the mechanical
support - that is exactly why these failures are endemic.

Incidentally, I have a pile of 12 laptops waiting for me to spend some
time repairing them. Most have broken power connectors. Some have
butchered power connectors where the owner attempted to repair the
connector. It's a very common problem that would easily be addressed
by a magnetic latch connector (as used by Apple) or mitigated by a
right angle power connector, which would rotate rather than peel the
connector off the board.

One of my Acer laptops has a right-angle connector and has surviced for about
ten years of in-vehicle use.

If you glue it first (with a decent material, NOT a brittle "superglue" type)
and THEN repair the solder work, you'll have a much greater chance of a long
term result.

What would you recommend instead? I use 24 hour epoxy.

Yep, that's my preference if people have the patience.

Some glues applied after soldering will actually pre-stress the
solder bonds and predispose the assembly to further failure.

Huh? Most glues shrink, not expand when drying. What type of glue
are you thinking of? The Duco and plastic model cement glues won't
stick to the plastic. The Urethanes work as good as epoxy, but is not
very good at gap filling or for non-parallel surfaces.

It doesn't matter whether they shrink/expand/whatever, they invariably seem to
cause some attempt at movement - and that applies mechanical stress to the
solder bond. If you glue first, then solder, that issue is avoided.