HP 33E Question - battery and NiCad batteries

[rprosperi]

DO NOT plug the adapter into the 33E until you know for 100% sure that the battery pack is good and makes good contact with the unit.

Due to a crappy power supply design (which uses the battery pack to regulate the power from the charger) if the battery pack is not present (or not tightly connected), the charger can destroy the ACT chip and/or RAM chips. The symptoms you describe are exactly those seen when an ACT is damaged, however it is not 100% certain your 33E is damaged, some of them can 'freak out' like this without permanent damage.

Check the voltage of the battery pack, it should be about 2.4-2.6V. Of course, also verify the polarity (the terminal near the top of the unit is MINUS). If that's good, then make sure the battery makes proper contact with the 33E terminals. If so, the unit should turn on. If the connection isn't tight, try inserting something behind the far end to push the contacts tightly against the terminals. Foam, bunched-up heavy rubber bands, or even folded paper often work fine to wedge the contacts together.

Good luck!