Is your old hardware made of gold, or just DIRT?

On Tue, 9 Oct 2012, Liam Proven wrote: I'll let others comment before I say too much about this one. The tin whiskers bit though... as much of a problem as they can be in some HV and RF circuits (including oscillator circuits*), a much larger problem that I've seen has been the use of those damned lead-free solder alloys with BGA components, where the joints fail due to thermal induced stress cracking (often due to the difference in the thermal expansion rates of the BGA component and PC board itself). Of course, this is still nothing compared to the capacitor plague problem... *I picked up a second hand USB host card that had grown significant tin whiskers at the terminals of the two feedback capacitors in one of the oscillator circuits. I fixed this permanently by reflowing and then replacing the lead free solder used for those two capacitors with good quality tin/lead solder. The board still has another issue due to apparent rough handling by the prior owner though, so it is still sitting in the to-do project box. I have a number of these very boards in active use, but the capacitors used in the oscillator circuit on that particular board were different from my other boards, and so far this is the only one of these I've seen that had grown tin whiskers.