Help Needed - My strange HP 41CX

[jbssm]

Hi all,

I have a HP 41CX fullnut (I already wrote because of this some time ago).

It's behaving very weirdly, so I'll enumerate what happens:

1 - It doesn't turn ON, by pressing ON

2 - Sometimes I can turn it ON by pressing BACKSPACE+ON (suggestion from a forum member)

3 - It always turns on by pressing BACKSPACE+ENTER+ON

4 - It retains memory after being turned ON and OFF, either in stack or in STO / RCL Command

5 - Everything seems to work fine, inclusive the Catalogue

6 - The exception is that when I press PRGM, or SST keys, it simply freezes

Now, I can't understand, I would expect that all simply worked or not, but this strange behaviour is giving me headaches.

Any suggestion on how to solve it?
Also, now I'm curious, what can be causing this?

Regards to all and thank you for this wonderful mailing list.

Edited: 23 May 2006, 5:49 p.m.

[Emmanuel]

Try this :

Yours.

[Karl Schneider]

"jbssm" --

Well, let's see... fullnut HP-41CX, cannot turn it on the normal way, problems with keystrokes that access program memory.

Perhaps your program memory might be corrupted, and that my very recent post would be helpful:

http://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/forum.cgi?read=92970

Regards,

-- KS

[Karl Schneider]

Emmanuel --

Thank you for the posted scan of the HP-41 "troubleshooting" letter from HP. I've stored it away for reference...

Based on "Yours", I assume that you intended to include an image in your reply to Mr. Lovin below:

http://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/forum.cgi?read=93122

-- KS

[Jan]

Have you tried a "master clear"? That is, turn off the calculator, press the backspace-key and keep it pressed while pressing the "on" key. Let loose of the "on" key first, then let loose of the backspace key. If everything goes well you should get a "MEMORY LOST" message and the 41 should then be back in its normal state. Remember to save any data and programs before the master clear (if you can) since all data/program registers will be erased.

regards
Jan

[jbssm]

Thank's a lot :)

I still couldn't get it to work, I'm trying the part were is says to wait 24h after some procedures, but this document is great :)

[jbssm]

Hi Jan,

I can't do a master clear cause it doesn't turn on the normal way.

Is there any way to make a master clear with the calculator already on?

[Emmanuel]

You are welcome! ;o)

If you ever turn it on and if it seems to be blocked, 

maintain ENTER and push ON repeatedly. 

And then the famous master clear :

maintain <- , push ON and release <- .

Yours.

Emmanuel

[Charles]

I've found this very interesting as I have an HP41 CX which emits a high pitched whine and no display when it is switched on. The volume changes if I press gold 4 but doesn't go away.

I've tried resetting it as described but it doesn't make any difference. I have another one that it completely dead. Both of these have gone through the German post recently- I'm wondering if they were x rayed and this has made a difference ? Any thoughts would be appreciated.

[jbssm]

Interesting ...

Did they had the batteries introduced when they went trough mail or not?

[jbssm]

It worked, it worked !!!

Thank you all very much and you Emmanuel for posting these instructions =)

[Charles]

No batteries.

[jbssm]

Strange ... I sold a 41CV some months ago that was working correctly, and after going to the UK without batteries also, it stopped working correctly (well, it managed to get to life though after some procedures).