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HP Forum Archive 09

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HP41 Auto off in 10 secs
Message #1 Posted by Mark Perlick on 16 Dec 2002, 12:57 p.m.

I have several HP41's, both CV and CX. One CV has a strange problem. When I turn it on, it will auto-off in 10 seconds instead of the normal 10 minutes. If I "XEQ ON" it stays on continuously. Any one seen this before?

      
Re: HP41 Auto off in 10 secs
Message #2 Posted by Vieira, Luiz C. (Brazil) on 16 Dec 2002, 1:04 p.m.,
in response to message #1 by Mark Perlick

Hi;

I have one with the same problem. Besides the fact it's a lot less power consuming, it's something tricky.

The LCD driver controlls the auto-off. I traded the LCD assy with another 41CV (fullnut) with corroded keyboard and now it works great. I saved the LCD, because it's working alright except for this.

Hope this helps.

            
Re: HP41 Auto off in 10 secs
Message #3 Posted by Erik Wahlin on 16 Dec 2002, 1:53 p.m.,
in response to message #2 by Vieira, Luiz C. (Brazil)

I saw this problem once when I had a bad connection at the main cpu board.

                  
Re: HP41 Auto off in 10 secs
Message #4 Posted by Vieira, Luiz C. (Brazil) on 16 Dec 2002, 3:00 p.m.,
in response to message #3 by Erik Wahlin

Hi;

that's new info! I was not aware of this possibility.

Thank you, Erik!

      
Re: HP41 Auto off in 10 secs
Message #5 Posted by David Smith on 16 Dec 2002, 5:14 p.m.,
in response to message #1 by Mark Perlick

If I remember right there is a capacitor on the CPU board that connects to a pin on the HP41 display module. The cap determines the time out period. A bad connection between the CPU board and the display will cause the problem. Also (but not as likely) a bad cap. The HP41 service manual is on the HPMUSEUM CDROM set.

            
CD HP
Message #6 Posted by Gina D on 16 Dec 2002, 6:34 p.m.,
in response to message #5 by David Smith

On wich CD so i can print this manual?

                  
Re: CD HP
Message #7 Posted by David Smith on 17 Dec 2002, 2:53 p.m.,
in response to message #6 by Gina D

I'm not sure which CD it is. I beleive it is labeled "service manuals" or some such. Also has the HP97 service manual which can also be a help with the HP67 and the woodstock machines.

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