#2 is this pin of the power supply connector. It's the +12V supply line, carrying 1.5 ... 2.0A. Note the slight discoloration of the connector housing, and the pin itself lost most of its plating when I removed it from the housing. There's been about 0.5V ... 1V drop across this contact. After an intermediate fix, the supply voltages with OK with little to no margin, and the fluctuations are gone.
The better fix for this (crap) kind of connector would be to cut it off and solder the wires directly to the pins - maybe I'll apply this later.
1000x this... Fukkin' insulation displacement connectors are a blight on humanity; barely sufferable for small signals and an abomination in any application where actual current-loading is present.
Note: It's not the insulation displacement part of the contact that failed but rather the contact itself. I've seen this kind of contact fail no matter how the wire was attached.
Of course, they're not suitable for small signals, you'd want proper gold flashed ones for small signals. The ones shown here are intended to use with some minimum current / voltage ratings (e.g. for power supplies), well above your typical small signal levels. Some minimum voltage / current is required to break oxide (or whatever) layers that form on their surface over time. Doesn't work out well all the time, as one could see here
I've had this discussion many times with many folks who know better than I do, and in conjunction with my own experience, I believe it is a chicken/egg thing. Wherever the electrical contact first breaks down, it causes heat, which affects the entire terminal.
Agreed, these single-wiper contacts are a horrible choice for anything carrying any current... but
adding insulation displacement tech to the mix is, IMO, a crime that should be punishable by testicular percussion over long periods.If you dismantle that terminal and strip the insulation off, I'll bet even odds you find the wire inside is either similarly heat-discolored, or blackened. And if not this one, the next one, or the next one after that. It is a fukkin' epidemic with these connectors. In all honesty, I don't believe it is a matter of if they will fail this way, but when.
Under any circumstances... I agree with your original surmise: Take no prisoners, cut & solder those bastards.
mnem