Musings and comments about our common interest
The assembled repair kit is a drop-in part for damaged-corroded battery contacts in the hp41c family of advanced scientific calculators. It solves the main issue that plagues old 41c units.
There is a cheap alternative when the damage is minimal. There are times when there is not too much corrosion, or where friction has caused the black support to appear (meaning the metal has disappeared in the contact area, but it is still available around). In these cases, there are two material that you need to know: Caig De-Oxit and the adhesive Aluminium paper.
Caig is an American company that produces several liquids to clean metals. I have been using its compounds for my hi-fi hobby for a long time - the sound and image really improve when you clean the interconnect contacts with De-Oxit; and they are maintained in good condition (and the golden or nickeled contacts preserved from dendritic corrosion) with Caig Pro-Gold.
Well, Caig De-Oxit works magic for removing corrosion. Use it with cotton sticks, rub them gently on the corroded part and you will see how the corrosion dissolves.
I have been using it recently on several deep corrosion cases on hp41c. Not only the battery assembly was corroded beyond repair, but also the circuit lines were completely green. As the battery assembly circuit had been destroyed by corrosion, the only solution there was the repair kit; but for the main calculator circuit, a generous application of De-Oxit led to a completely clean machine that worked from the first second it was reconnected. I must say that I have also failed with other calculators, but that may be due to additional damage elsewhere.
Tomorrow I will show to you the adhesive conductive film