HP-25E GPS ACT Version

[PANAMATIK]

(06-25-2017 10:05 PM)rprosperi Wrote:  Bernhard can clarify to be 100% sure.

You clarified this already.

What is the worst case when buying a "not working" HP-25, what cannot be seen from outside?

1.) Display defective, segments are missing.
If the display has missing segments, there is no way of repair. Only the new Woodstock LED module could be installed, but it has smaller digits and a different look.

2.) Keyboard buttons non responding due to corrosion.
Even very corroded keyboards can be brought back to good responding within one day by using DeOxit red and a small steel wire to clean the contact area inside the pores below the buttons.

3.) Electrical fault by corroded wires or defective components.
Provided you are equipped with tools to replace components, all electrical damage inside the calculator can be repaired. Corroded traces could be easily repaired. Switching power supply can be easily repaired by replacing the 2 transistors and zener diode (less than half €). The ACT can be replaced (80,- €). The most difficult repair would be to replace also defective display drivers.

In every case when buying the new ACT, I would offer you to send the complete calculator for a guaranteed repair.

Bernhard