|HP41CX scary moments (or: There is a Poltergeist with my calculators)|
Message #1 Posted by Vieira, Luiz C. (Brazil) on 15 Jan 2003, 4:29 p.m.
A few days ago I posted a message about an HP25 with a strange behavior. Now it's the time to try to figure out what happened with my HP41CX's time module.
I took it yesterday night and turned it on. [MEMORY LOST], no matter. But no switching to OFF; instead, an annoying, persisting [MEMORY LOST]. Last time I saw it, my HP41C was sent to repair at HP Service Center and returned with a new 1LA701 (RAM chip with first 16 registers, the ones used by the system to store the stack registers, ALPHA characters and those well-known synth regs: "a", "b", "d", "Q",...). And the HP41CX was with the same symptom. If this is the cause, I can test a spare 1LE701 I have in a broken HP41C motherboard, but my 41CX is a halfnut... I cannot se a way to transplant organs from a fullnut to a halfnut.
The [MEMORY LOST] also had a brief flashing, about 1 sec. span, and the BAT annunciator lit after a few seconds. I remember I read about time module crashes and that it needed to be removed for a few minutes and then reinserted. In an HP41CX? How could I do that???
Well, remove batteries and wait for a while. I decided to change the batteries in the pack for new ones and tested the removed pack in an HP41CV, halfnut too, and the BAT annunciator stood still: did not lit on. Batteries O.K.
I inserted the batteries back in the HP41CX and the [MEMORY LOST] remained, but this time the [<-] cleared it. Wow! Let's put my heart back in my chest. And for a last test: [SHIFT] [ON] and... blank display! No watch display, no turn ON, no nothing. Remove batteries, remove the heart from the chest and keep in hands again, wait for a while (I stop smoking about 8 years ago, and I'm lucky not smoking today...).
XEQ 01; this time, instead of [SHIFT] [ON] I tried [CLOCK] and... There you are, my dear; where have you been for the last hour?
Well, what to conclude? For me, a possible bad contact BUT complete isolation from the battery connector caused the time module to behave erratically. The system interruption caused by [SHIFT][ON] was not successful to bring it back from this condition, but [CLOCK], as a function, takes a different route. Maybe if I left the calculator for a couple of hours without the batteries it would get back O.K., but I was in a hurry to know what was going on. I hope this experience is useful to someone else.