I still continue searching my main board problem. I cleaned every contact, i check every diodes, condensators and resistor the best i can. I reassembled the calculator and it works great for about 1 minutes : great improvement over the 1 second i was use too...
I realize another things : in the minute of good working, nothing anormal is heard but the calculator is slowly beginning to give a distortion noise comming from what i think is the main board. When the noise is steady, the calculator stard do freegames again (about 1 minutes).
I thought it was the piezospeaker giving that noise so i removed it. reassembled the calculator and the noise is still there!!! WHAT ELECTRONIC component can do noise in the mainboard of a HP-41CX mother board?!?
Thanks for help!
Edited: 21 Oct 2003, 5:27 p.m. after one or more responses were posted