Dry soleder

A close visual inspection, performed with stereomicroscope.

Consider any dull joints as very suspect.

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Just my $0.02...

Hello Guest,

A simple way is to carefully use your eyes, if you are a younger person.

Generally a magnifying lens or microscope is not needed, unless you are aged 40+.

Dry joints generally look grey, misshaped and wrinkled on the surface (like older people).

Good joints look polished, and rounded edged, (like younger folks).

The other way, a wee bit more complicated, is to use a low-current ohm-meter or continuity tester, between one component connector wire and the other end of the circuit component connector wire - be careful in electronic circuitry not to damage any components, IC's transistors, diodes etc.

There is a third easy way, and that is to re-solder everything, which normally takes care of dry solder joints.

If this problem is on a printed wiring (commonly mis-called as "Printed circuit") board, you may well have one or more broken tracks, these are more easily seen if you look at the board with a very bright 150Watt or 200Watt light bulb switched on, behind the board.

Kind Regards....

"unless you are aged 40+"

I resemble that remark...

Sparkstation, if you deal with pc boards with SMDs, you need magnification, unless you have superb vision.

I used to have pretty good eyesight, but that was before SMDs were in wide use.

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Just my $0.02...

Hello The JMAN

Back in the good old days of milk bottles with dull red lights in, we could easily see if a radio, (wireless for the folks in the UK), was working properly.

As time went on, things began to shrink, as if they had all partaken of the smaller side of Alice's mushroom.

Last time I worked with, and designed equipment using vacuum tubes, (valves for folks in the UK), they were the tiny and highly efficient Nuvistor triodes.

Yes, I must agree, that in recent years my vision is not as clear as it once was, but I resist purchasing optical lenses in frames to assist my vision, not wanting to make a spectacle of myself.

SMD's are planning on becoming smaller, with nanotechnology developments.

Capacitors and Inductors are not really needed, most are replaced by clever circuitry inside an Integrated Circuit, which simulates such components.

The problem then is, that we wont be able to see the components at all, unless we have an electron microscope.

Kind Regards....

Thermal cycling will also accelerate cold/dry solder failures too (-20 to +50C is a good range). The best method is a combination of visual inspection, vibration testing, and thermal cycling. Of course, as usual, an ounce of prevention is worth a pound of cure. It's best to have the soldering process tweaked such that you don't get cold/dry solder joints .

Thomas DeSmit