HP 67 Circuit Board

[Jeff_Birt]

(07-11-2022 03:58 PM)metawops Wrote:  Okay, back to on-topic. Attached is a photo of a part of my 67's circuit board to which the card reader is connected – do I have to worry? Is this a serious problem? Should I repair this with small wires?

That does not look bad. I would lightly scuff the area with a fiberglass pen, that should get most of the corrosion off of there. If there still looks like some corrosion in tiny crevices treat with vinegar or citric acid for 20 minutes or so then flush with water and clean with alcohol. The last step is to tin the bare copper with solder to protect it.