|Re: HP 41CX Auto power-off problem|
Message #2 Posted by Dan Grelinger on 17 Apr 2009, 9:10 p.m.,
in response to message #1 by Jose Poyan
I can't help very much, but here is what I know, or suspect:
There is no normal function that would change the HP-41's auto-off functionality as you describe. Therefore, the manual will be of no use to you with this problem.
When the clock is in the display, the calculator is actually running a routine every second to update the display. I assume that if you use the calculator, or have a user program running, it won't turn off. This would indicate that it is the auto-off functionality that is turning the HP-41 off, just not after the 10 or so minutes it is supposed to wait.
I believe, from some long ago reading, that the auto-off functionality is located in the display controller. Not knowing much about the internals, I would not be able to rule out a contact problem (there are plenty in an HP-41), but it may be a faulty display controller.