The Museum of HP Calculators

HP Forum Archive 14

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HP 01 calc/ watch repair
Message #1 Posted by Sam on 11 Jan 2005, 8:23 p.m.

After a list member graciously answered my question about how to setup the time for the HP-01, I found out that keypad is messed up. When I press any digit, I either get 3 (if I press the upper row) or 8 (if I press the lower one). Can someone help me with a place to repair the watch if one exists?

Thanks Sam

      
Re: HP 01 calc/ watch repair
Message #2 Posted by Randy on 11 Jan 2005, 9:53 p.m.,
in response to message #1 by Sam

The news is not good: http://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/archv014.cgi?read=65455

            
Re: HP 01 calc/ watch repair
Message #3 Posted by Tony Duell on 12 Jan 2005, 6:40 a.m.,
in response to message #2 by Randy

Alas, I have to agree with that. I had a chance to handle the module from an HP01 at the last HPCC meeting. It consists of 2 ceramic 'circuit boards' glued together, the keyboard contacts being on the top one. I believe that inside, there are the bare silicon dice (chips), bonded out (connected) by fine gold wires to traces on the lower 'board'. These chips are not in packages, there's not way to replace them even if you could get spares (and AFAIK they were only used in the HP01). The display, battery contacts, crystal and a couple of passive components are soldered to the back surface of the lower board and could, in theory, be replaced, but they're unlikely to fail anyway.

The 2 boards are connected by a zebra-strip like connector on the right edge, which can be pulled out. This sowuld be worth cleaning if some of the keys are totally dead.

To return to the orignal problem, if this had been a classic-series machine (related architecture), I would have suspected a C&T chip failure, or maybe ROM failure. But there's no way to replace those on the '01

                  
Re: HP 01 calc/ watch repair
Message #4 Posted by David Smith on 12 Jan 2005, 6:46 p.m.,
in response to message #3 by Tony Duell

One may also try a trip through an ultrasonic cleaner (use three passes with fresh distilled water in each pass). Shake out as much water was possible and then let dry. I use an oven on LOW (<150 degrees F). The high impedence circuitry on the boards is easily messed up by any accumulated gunk.


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