Hi,
I am wondering what the general consensus is regarding the fragility of the HP 25. Does the HP 25 survive an over voltage condition as seen when the charger is used without a battery pack ?
I believe the HP 25 uses PMOS technology which is less sensitive to overvoltage than CMOS or NMOS - is this true ?
I have looked through the archives and found plenty of cases where a HP 29C (and to a lesser extent the HP 25C) is destroyed by the charger over voltage when the battery is not making good contact or is not fitted. Most authors point to the CMOS ROMS as being destroyed, rendering the calculator useless.
I do not recall seeing any examples of a HP 25 or 21 being destroyed in this manner.
What is your experience with the 25/25C/29C ?
Regards, tjw.