|Re: Low battery, CLOCK and [SHIFT][ON]|
Message #9 Posted by Victor Koechli on 23 July 2003, 4:02 a.m.,
in response to message #6 by Vieira, Luiz C. (Brazil)
Low Batteries are usually the cause for this beaviour. You can easily see why:
Most 41s (all I have ever held in my hands, anyway) produce an audible sound when the CPU is running. Just program an eternal loop and start it, then hold your ear at the back label - you will hear a low hissing noise. Press R/S to stop the program, and it's gone.
When you press [SHIFT] + [ON], you will hear the CPU run as it turns the calc off, then back on. After that, the CPU will run until it's time for the first display update. That is, in CLKTD mode, where seconds are not displayed, the CPU will run continuously for up to 1 minute, until it's time to turn the minutes. After that, the 41 sets an internal timer, and the CPU will turn off until it's time to update the diplay again. Do this in CLKT mode, and you will hear the CPU quickly turn on and off every second after the initial continuous period is over.
As this can use quite some battery power, it's easily possible that you see no BAT indicator, but the clock will still not turn on. Same with the Card Reader, BTW.
Besides that, I remember reading somewhere that the 41 knows at least two different low power levels, and obviously only one can be communicated via the BAT indicator. Don't know which one, however.