"Pete C." wrote in message
...

PrecisionmachinisT wrote:

"Karl Townsend" wrote in message
...

Leaving it on all the time helps too.

Indicates possible thermal expansion of a solder joint or
component...oftentimes, you can poke around with toothpick or something
to
locate the culprit.

Beware of switching power supplies, they can produce a fairly nasty
shock.

Hairline thermal stress solder fractures around component leads are
fairly common. Back when I helped a friend at his repair business any
Sony receivers that came in for repair automatically got a manual
resolder at all points (heat and add a bit of fresh solder) as that was
by far the most common failure. If you looked under a good magnifier you
could see the circular fracture around the component leads.

Wave soldering is notorious for leaving cold joints, especially at any point
where fairly large components are mounted, things like cable headers,
rheostats and so forth etc.

Reason being, the molten solder is not in contact for a long enough period
of time for the leads to heat up sufficiently.