Originally Posted by
Mrmiata
Beyond me how those solder joints are wiggle jiggle sensitive.. and propping up the wires fixed it to get it to the shop... I'd say there's a little more to this than just solder joints.. bad plug connector or something along with it..
Actually, the solder around the pins breaks and forms tiny cracks, by putting pressure on the wires in the right direction, you force the pins to make contact across the gap that forms.
I first ran into this in the Audio/Squelch boards of Motorola Micor radios in the 1980's. They used feedthrus that were riveted in as contact paths between the two sides of the boards. Solder would fracture under the stress of the board heating up and cooling, mostly in the winter when the heater was turned on, but vibration also seemed to cause it.
Motorola changed their design soon after, mostly because they went from two sided to multilayer boards.
NOT TO SAY that bad crimp pins on the ends of the wires is impossible....