The Museum of HP Calculators
HP Forum Archive 09
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|HP 42 S flaking out|
Message #1 Posted by Edi von Engeln on 11 Sept 2002, 10:16 a.m.
Recently my 42S started “flaking out”. 1) The self test says okay but periodically instead of going to sleep it starts beeping steadily and then it resets the machine 2)after a delay in keystrokes I think that the decimal point or some series of key strokes with the decimal point also imitates a machine reset. Any ideas?
Perhaps some cleaning of contacts would work if I could open it
|Re: HP 42 S flaking out|
Message #2 Posted by Randy Sloyer(US) on 11 Sept 2002, 10:23 a.m.,
in response to message #1 by Edi von Engeln
Are the batteries fresh? Are you able to check the voltage of the 3 battery stack during operation? Anything below 3.8 volts and you will have trouble, maybe sooner. I have found the battery annunciator to not be a reliable indicator of battery condition.
A liquid spill in the keyboard may cause this behavior as well. Coffee, cola and others would certainly make a mess of things.
|HP42S Not Working|
Message #3 Posted by Don Keller on 19 Sept 2002, 10:40 a.m.,
in response to message #2 by Randy Sloyer(US)
The batteries went dead, and I didn't replace them even close to right away. It was probably 6 months later that I decided to replace the batteries. Now, after replacing the batteries, I turn it on and get all the pixels in the display are 'on'. Any buttons I press, results in a beep. I've tried the self test - beep. I've tried the reset - beep.
Is it a lost cause?
|Re: HP42S Not Working|
Message #4 Posted by Randy Sloyer(US) on 20 Sept 2002, 10:43 a.m.,
in response to message #3 by Don Keller
The beep means at least the processor is running but perhaps the ROM fails checksum?
Anybody know for sure?
Could it be a bad battery? I would check them if you can.
|Never give up...|
Message #5 Posted by Vieira, Luiz C. (Brazil) on 21 Sept 2002, 6:52 p.m.,
in response to message #4 by Randy Sloyer(US)
have you already tried to briefly (a lot briefly) shorten the batteries' terminals? Get a little piece of conductive metal, preferably a wire OR a thin paper clip. Carefully remove the batteries' cap. WITH THE BATTERIES INSIDE THEIR COMPARTMENT, briefly (a lot briefly) shorten the batteries' terminals. Keeping the batteries there will NOT ALLOW voltage to go upper than the 4.5 Volts. Place the cap back.
Whatever happens, let us know.
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