Part Number: SN74LS257B
In an order recevied last week from mouser included several tubes of 74LS DIP parts in what I'd call questionable condition but I'm not an expert on oxidation, other than to say these parts just don't look like the "new" parts I'm used to, but I'm from the old-school "leaded" days!
In the best cases the pins have a flat or "frosty" look. The worst of the bunch are these 74LS257s which not only have a golden-brown (old copper) appearance, but when looking under the scope I think I'm looking at surface oxidation on many pins. It's tough to see the color with the scope LED lighting, but it's there. I also have a tube of 74LS02s from late last year which also has a very similar look.
Mouser said they reached out to TI which claimed there's no sign of oxidation and this is the result of the "lead-free" coating which I totally suspect is BS. So, is this "normal" or are these defective?
I hope these images get resized, becasue when uploaded they were full-sized which is basically worthless...
