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HP Forum Archive 13

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HP-41CX
Message #1 Posted by Gary on 19 Oct 2003, 8:04 p.m.

Hi, I have a HP-41CX that turns itself off after only about a minute. Everything else seems to work. Any suggestions?

Thanks

      
Re: HP-41CX
Message #2 Posted by Fred on 20 Oct 2003, 9:29 a.m.,
in response to message #1 by Gary

Learn to calculate quickly?

      
Re: HP-41CX turning off quickly -- was discussed here recently
Message #3 Posted by Paul Brogger on 20 Oct 2003, 10:42 a.m.,
in response to message #1 by Gary

I'm no 41 expert, but I believe this has been discussed here recently. If I remember right, it's either bad contact between the keyboard and the cpu board, or it's a bad capacitor on the cpu board.

But don't take my word for it. Search the Forum or the Archives -- I'm sure you'll find some recent discussion of this very problem.

Good Luck!

            
Re: HP-41CX turning off quickly -- was discussed here recently
Message #4 Posted by David Brunell on 20 Oct 2003, 10:58 p.m.,
in response to message #3 by Paul Brogger

I've made a habit, anytime I open a 41 for the first time, of replacing the two electrolytic capacitors with tantalum units. One is a 470 uF @ 6.3 V and the other is a 100 uF at 10 V. I believe the former holds the memory while changing batteries and the latter controls the shutoff time.

I had one 41CX that was eating batteries even while shut off, and it turned out to be a leaky 470 uF cap.

                  
Re: HP-41CX turning off quickly -- was discussed here recently
Message #5 Posted by Gary on 26 Oct 2003, 7:39 p.m.,
in response to message #4 by David Brunell

Thanks David, I will change the capacitors and let you know the results.


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