Re: Memory Lost 41CV Message #2 Posted by Vieira, Luiz C. (Brazil) on 2 Apr 2004, 11:12 a.m., in response to message #1 by Elio
Hi, Helio;
in most cases, this sort of message appears when there is a bad contact between the keyboard's PCB and the calculator's mainboard (circuit board, where all components escept the LCD and drivers are assembled). Please, have a look at the image below:
Compare this image to your HP41's LCD and see if you can identify. It's more likely that it is a fullnut. In this case, what's written above is applicable, and in this case it's necessary to open the calculator and clean the contacts between the boards.
Halfnuts usually do not show this message this way, unless you have faulty components or a cold solder in one or more of the CPU's teminals.
The other possible (and very remote) case happend once with my old HP41C. Suddenly it did not do anything but showing a slightly blinking [MEMORY LOST], almost one blink at a second. In this case, the calculator was sent to HP in order to be repaired. It was necessary to turn the calculator against light to see the slightly blinking. It was a faulty RAM IC. THe fullnuts HP41C have two RAM IC's: one with 16 registers used by the system and another one with the 64 registers available for the user. Yes, we all "see" 63 registers, but there is a 64th. one that must provide 3 bytes for the permanent .END. and consquently let 4 bytes always available. This one cannot be a numbered register.
Let us know if you need guidance. Otherwise, Fix That Calc is always a second choice.
Success.
Luiz (Brazil)
Edited: 2 Apr 2004, 11:15 a.m.
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