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HP Forum Archive 15

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HP41C/CV/CX Self Test
Message #1 Posted by Mike T. on 14 Feb 2006, 7:45 a.m.

I suspect that the answer is no but I'm going to ask anyway as there are a lot of heads out there that are much wiser than mine.

I'm considering buying an HP41C/CV or maybe CX - I would like one in a nice clean condition and of course it has to work. Earlier SPICE series machines had a self test, and the later Voyager series had both a self test and a keyboard test. Is there a similar way of testing that an HP41C/CV/CX is working properly...?

Thanks

Mike T.

      
Re: HP41C/CV/CX Self Test
Message #2 Posted by Raymond Del Tondo on 14 Feb 2006, 8:42 a.m.,
in response to message #1 by Mike T.

Hi,

the HP-41 doesn't have a similar self-test built-in,
but you can check the most important things very easily.

I'd reset the machine first, clearing it's memory:
While the unit is off, press and hold the backspace key,
then press the ON key, then release both.
The unit should show 'MEMORY LOST'.

Press the bar keys, from left to right.
The first bar key turns the calc on,
the second switches to USER mode,
the third to PRGM mode, and the 4th to ALPHA mode.
If these modes are shown by the associated
annunciators in the display, these keys work.

Then switch back to 'normal' mode by pressing PRGM again.
Press [XEQ] [ALPHA] S I Z E [ALPHA] 0 0 0 , then press [PRGM] again.
On an empty CV or CX unit, the display will show '00 REG 319' .

This way you'll see that the RAM chips are there,
and are likely to work.

To ckeck if the display works, press [ALPHA],
then ABCDEFGHIJKLMNOPQRSTUVWX .
If you hear a beep when entering the X,
you have entered 24 characters. This is ok;-)
Now turn off ALPHA by pressing [ALPHA],
then press [ALPHA] again.

The display should show the string shifting to the left in short intervals.

You can also check if all keys have the same tactile feedback
by pressing them one after the other,
and check basic functionality by doing some calculations.

If nothing unxpected happened so far,
the unit is likely to work.

Of course there are always chances for hidden defects,
like broken screw posts or corrosion,
but this will be visible from the outside;-)

In my experience the above key sequences
show at least that the basic machine works.

There exist some Diagnostic ROM modules for the HP-41,
which had real self-test functions built-in,
but these weren't available to the public,
and thus are next impossible to get.

HTH

Raymond

Edited: 14 Feb 2006, 8:47 a.m.

            
Re: HP41C/CV/CX Self Test
Message #3 Posted by Mike T. on 16 Feb 2006, 5:19 a.m.,
in response to message #2 by Raymond Del Tondo

Thanks - Unfortunatly I was out bid again...

One day.

Mike T.

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