Re: 41CX with Interesting Problem Message #5 Posted by Howard Owen on 29 July 2005, 12:21 p.m., in response to message #4 by Vieira, Luiz C. (Brazil)
Yes, I thought it was interesting. 8)
Nothing unusual shows up in CAT 2. The machine came with an I/R module and a surveying module, but I've removed those. There was also a protected program in memory that went away when I reset the machine. I haven't asked the seller about that because he looks to be a surplus/second hand dealer with no other calculator stuff for sale. The machine came in a bundle of other machines from TI, Casio and Sharp. All that suggests the seller won't know anything specific about the machine.
The CLX key works the same in program mode. That is, pressing SHIFT-CLX in rapid succession enters "CLX" into the program. Pressing SHIFT, then SHIFT CLX rapidly deletes the current program line.
My theory is either that there there is internal corrosion that is affecting the CLX key press by itself due to increased resistance. In this scenario that resistence is overcome briefly by pressing the shift key. Or else there's a problem in the decoding of the key presses in the CPU. I guess it's also possible that it's the classic broken lower post problem. But pressing one or both keys forcefully doesn't seem to affect the behavior.
There's no sign of corrosion externally, but I sure hope I find some inside. There would be hope of fixing things in that case, whereas a bad CPU is probably the end of the line, since I don't have a spare halfnut CX. On the other hand, I find that I can reliably operate the key now that I have the hang of it. I think I'll make this my main 41 for a while. It has a scratch across the display too, which makes it less valuable for resale. My practice is to hold on to flawed but servicable equipment for my own use and sell the better quality stuff. I figure I add value through my selectivity in the base machine and the add-ons that way.
|