Hi;
I'd like to help, but I must confess I did not understand the problem.
When you switch the calculator ON for the first time, what do you see? The HP41 normally shows the X-Register contents and any active annunciators, except for ALPHA, PRGM and SHIFT, of course. The only way you have a blank display when you turn the calculator ON is by storing a blank ALPHA in the X-register (at least this is the only way I know), considering the calcualtor is working fine.
Now about yours: you mention a standby mode between key presses. Standby mode is exactly this: after an operation is performed and before the next key is pressed. In this case the calculator should show something: X-Register contents, a message, ALPHA contents, program steps or the flying goose. Yours go blank-display between key presses?
What about these:
- ALPHA mode
- PRGM mode
-after an AVIEW or VIEW nn
What happens in these cases?
If the LCD shows the flying goose and function name + NULL when key is held down, there is something more than bad contact in the LCD's module.
At least it seems to me that is. I'd liek to know a few more about it.
Success Adn best regards.