Message #1 Posted by Steve Hunt on 17 Dec 2011, 11:34 a.m.
Hi folks - new to the forum so please go easy with a "newbie".
I have an HP41CV (Fullnut I think you call it) which has seen better days - badly corroded battery terminals, and intermittent contact between the logic board and keyboard. Rather than scrap it, I pulled it to pieces and hard-wired the logic board to the keyboard. Temporarily I've connected a 6v supply directly across the appropriate keyboard traces.
It doesn't work! Here are the symptoms:
At power-up the display shows the "flying duck" in the leftmost display position and the PGRM annunciator is on. None of the keys has any effect except:
* Pressing the ON key causes the display to briefly show "MEMORY LOST" and the beep to sound before going back to the original display.
* Pressing R/S changes the display to "0," at the left and "00" at the right. Pressing R/S again puts it back to the original display.
Before throwing it in the bin I wondered if those symptoms give any pointers to what the fault might be.
I've very carefully check my hard-wiring of the logic board to the keyboard - everything looks correct with no shorts.
Grateful for any help,