Opening and trying to fix a leaked HP 48S

[ytterligare]

(11-20-2020 05:00 PM)lyuka Wrote:  As the keyswitch of the pioneer series are made of carbon contact,
any kind of acid treatment won't work, or do harm to the membrane circuit.

It was possible to transplant the membrane switch, but it was very difficult.
Deterioration of the membrane switch itself is wear and cannot be repaired.

I give up.
After keeping few hours the lower part of the keyplate submerged in vinegar 6% ( lot of bubbling and chemical reaction), rinsing with water and isopropyl alcohol, the first row of the keyboard is still dead, no sign of life whatsoever.

Alas, one 48s less, survived in the world
Will probably sell it as scrap for repair on ebay.

Thank you everybody !
A.