|Re: HP41CX - Strange turning-on behaviour|
Message #4 Posted by Geoff Quickfall on 4 May 2011, 2:20 p.m.,
in response to message #3 by Norman Dziedzic
1. ensure the calculator is off
2. hold the CLX key first, then press the ON key while holding
the CLX key.
3. release keys.
4. should have MEMORY LOST displayed.
1. remove batteries
2. hold the CLX key first, then press the ON key.
3. install batteries and repeat procedure ONE.
1. remove batteries and short the far left to the far right
2. install batteries and repeat procedure ONE.
1. remove batteries and leave alone for 24 to 48 hours or longer!
The problem is, the status of the calculator became corrupted and since "ON" is an assignable function, all the keys may have been assigned the "ON" function. Purely speculation! In any event the processes above are meant to initiate a 'clean state' HP 41CX. The continued buggy state arises when the continous memory function (capacitor) causes the calc to retain the corrupted state.
Once you have finished I recomend and use a "LO" program assigned to the shifted R/S (VIEW) key. The code is as follows:
When you are finished with the calc turn it off with the LO function assigned to the shifted R/S (VIEW) key. This has the affect that when the ON key is accidentally pressed while residing in your bag, the calc turns on and executes (SF 11) the program residing in the active memory (LO); which simply commands the calc to immediately turn off.
Of course the next step is to terminate the LO program to gain access to the calc. This is done by turning on the calc and immediately press the R/S key. This haults the LO program midstream and allows you to manually exit the program and run whatever you want.
There is one more reset method but use with your own discretion. It has worked for me but as a last resort on an unusable machine that refused to reset using the above procedures.
1. remove batteries and install them in reverse polarity.
2. press and hold the ON key for a few seconds.
3. release and remove the batteries and install correctly.
4. repeat procedure ONE.
Edited: 4 May 2011, 2:25 p.m.