Thank you in advance for helping me.
I have a hp-34C fully working but everytime i switch it on/off i get "PR error" and my program is erase. I clean the switch contacts and the calculator didn't switch off alone by itself anymore but i still get pr error when powering it on. What can cause this situation?
By the way, can someone gime me a tip for opening the case of this series : every time i open the case i pray that the case will resist the high pulling i give to separate the two shells (the bottom of the case is very hard to dissambled without a great great force).
Fred