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HP Forum Archive 09

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HP-11C semi-dead or what ?
Message #1 Posted by Erich Neubacher on 10 Sept 2002, 10:52 a.m.

first of all: I can't accept the fact that a HP-Calculator doesn't work because of bad material, which fades away, or because of low accuracy in the manufacturing.

It all began with a HP-11C ( USA 2552A03475 )I bought some weeks ago. It passes all standard tests. All was very well. Then some day I want to have fun with my little toy and played around. Hmm, what to do ? Another key-board-test, but what's that, the display is frozen. Have I pressed a wrong key or what ? panic....but remember old 41C... get off the batteries...wait some seconds...and start again. NOTHING....Hmmm....get off batteries put 11c on the shelf some days....put in batteries...start....NOTHING...pressing randomly some keys...oops, he is alive, works some seconds, but then gets frozen again or doesn't start if turned off....same procedure many times. The machine doesn't work reliable, but the core seems OK. I suppose it is in a special state, some circuit/IC is in a wrong branch or something like that. Mechanical all seems OK.

I read some articles about dead 11C in this forum. Yes, I shortcut the battery-contacts...WITH < shudder > and without batteries. Maybe now the machine is really dead ;-)

Is there anyone out there, who can help me ?

Thank You.........Erich Neubacher

Re: HP-11C semi-dead or what ?
Message #2 Posted by Vieira, Luiz C. (Brazil) on 10 Sept 2002, 12:31 p.m.,
in response to message #1 by Erich Neubacher


I had an HP12C in hands with a problem about the same; the difference is that it froze for good.

After resodering all of the IC's terminals, it became the same, good little girl "she" was. If you want to do so, say, to open the calcualtor and solder the ternminals, have a look here.


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