[Elecraft] Solder rot?

[Brian Jones]

Anyone got any thoughts - my K2 has been playing up with the serial
connection so I investigated and ...

The entire serial board is no longer the neat bright solder joints that were
there when I made it. Instead almost every joint is a dull matt grey and in
many places there are bits of white dusty solder around the base of the
joint, in several places joints are connected by this 'dust'. It's almost as
if the solder has rotted.

I do have several different spools of solder and, who knows, which one I
used 8 years ago. However they are all traditional 60/40 Sn/Pb flux cored
from reputable manufacturers so ought be OK. It is only this one board that
has the problem, all the others still show nice shiny joints.

No problem it's just a few hours work to remove, clean and then replace all
the components (and a joy to do since I get chance to use my new retirement
gift of a Metcal solder station) I'm just curious as to the cause, bad
solder, a board that hadn't been cleaned of flux properly, anything else?

Brian G0UKB