Lew.
You may be onto something with the multi-prong plugs. It is likely that the individual male and female pins are crimped. Over time with dissimilar metals, wire and pin, along with a bit of humidity, electrolysis is possible/probable. I have with some gear pulled these connectors apart, cut the wire and soldered it back on to the pin. It is a real PITA since the new connection has to fit back into the plastic holder.
You could of course simply bypass the plugs altogether and solder the pairs.
Good luck with the Witch hunt.
You may be onto something with the multi-prong plugs. It is likely that the individual male and female pins are crimped. Over time with dissimilar metals, wire and pin, along with a bit of humidity, electrolysis is possible/probable. I have with some gear pulled these connectors apart, cut the wire and soldered it back on to the pin. It is a real PITA since the new connection has to fit back into the plastic holder.
You could of course simply bypass the plugs altogether and solder the pairs.
Good luck with the Witch hunt.