Re: Finding a cold solder joint...

Are there socketed parts on the board? I'd pop each of those and check for
oxidation first.

As for finding cold solder joints. Depends a lot on the board and the
problem. Typically I just get a bright light and work my way through the
board with a soldering iron looking for the obvious problems. Some boards
I've worked on have qualified for the "entire cold solder joint" award.
Also -- I like to concentrate where previous operators have taken a shot
at repairing the board. A lot of times their work has been substandard.
If it's like a tempest boardset with an interboard-connector I'll make
sure to reflow all of those joints -- very likely to be a problem.

Then of course all of the above is not guaranteed to fix anything. I've
been through my TimeScanner board a couple of times now over the years.
It STILL wants a love tap to start up every now and then. *grrr*
Some day I'll just reflow the whole thing.

Which board is it?

One of the most unique "fixes" (we use that term loosely) that I saw an
operator do was to duct tape a couple rolls of tokens onto the top of a
board that was mounted horizontally in a cabinet. This had obviously
been there for a while. (I was looking at it 'cause the monitor had died).
His response - "I found if I pushed on the board it worked -- so I figured
the tokens would weigh it down." And so it did -- the duct tape was a nice
touch.. And yes, I fixed the board while I was working on the monitor --
a cold solder joint.

Kurt

> I've got a couple of boards with intermittent graphics problems that go away
> when the board is flexed, which leads me to conclude that I've got a cold
> solder joint somewhere that needs to be reflowed. But for the life of me, I
> can't figure where it is -- I've tried just wiggling components, but that
> doesn't seem to narrow it down (wiggling different components seems to fix
> it different times).
>
> Are there any tricks for figuring out where on the board the problem lies? I
> don't have any schematics, otherwise I'd try to track it down based on the
> symptoms, rather than just blindly wiggling the parts...
>
> Thanks,
>
> -atw
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Received on Fri Dec 14 09:31:03 2001