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From: conte@crest.crhc.uiuc.edu (Tom Conte)
Newsgroups: comp.sys.handhelds
Subject: Re: HP21, HP25 repairs
Message-ID: <1991May10.165501.2070@roundup.crhc.uiuc.edu>
Date: 10 May 91 16:55:01 GMT
References: <9361@idunno.Princeton.EDU>
Sender: news@roundup.crhc.uiuc.edu
Reply-To: conte@crest.crhc.uiuc.edu (Tom Conte)
Organization: Center for Reliable and High-Performance Computing, University of Illinois
Lines: 28

In article <9361@idunno.Princeton.EDU>, woodhams@phoenix.Princeton.EDU (Michael Woodhams) writes:
> 
> Does anyone know how to open up these calculators?

This is only a partial solution, sorry, but...

To open up a woodstock-series calculator:

Turn the calculator over.  Have a #0 phillips handy

Use a pin to remove the two lower rubber feet (they are not glewed in,
so you can pry them out).  This will reveal two black screws.  Remove
The screws.  Slide the back *up* relative to the front.  (There is a
J-style hook between the front and the back at the base of the keyboard).
The two parts should come off revealing:

One printed circuit board connected to the calculator's keyboard by
a line of spring-clip pins.

The battery contacts are round soldered-on disks that extend from the
PC board.  I've found that in mine the solder connection to these disks
sometimes gets a fine hairline crack in it.  Re-soldering the connection
might fix some of your problems.

------
Tom Conte	  Center for Reliable and High-Performance Computing
 conte@uiuc.edu   University of Illinois, Urbana-Champaign, Illinois
  Fast cars, fast women, fast computers