N Cook wrote:

A 200W combo, UK made 2002, with one solder joint to a small on-end
electrolytic failed
so could be just due to vibration/resonance.
But it is on a board with obvious conical solder joints so perhaps the most
likely inherently weak joint to fail first. The larger (heatsinky) joints
are shiny and conical, redone by hand with junk solder maybe, but all the
other small joints look horribly grey. On the other board all conical joints
but all bright silvery colour. What is the consensus of the panel - redo all
the grey joints with Pb-Sn solder and leave the bright ones, or if it aint
broke - don't poke. ?

Lead-free solder joints do look grey. And they have poorer resistance to
vibration induced failure AIUI.

If you use Sn-Pb solder to repair a board with PB-free you're *breaking the law*
and Mr Lead Free Man may come along and fine you £5000 !

Graham