Path: utzoo!utgpu!jarvis.csri.toronto.edu!clyde.concordia.ca!uunet!mcsun!cernvax!chx400!ugun2b!ugobs!bartho
From: bartho@obs.unige.ch (PAUL BARTHOLDI)
Newsgroups: comp.sys.atari.st
Subject: Re: Need Mouse Info
Message-ID: <508@obs.unige.ch>
Date: 12 Jan 90 14:56:52 GMT
References: <1782@mrsvr.UUCP> <7051@b11.ingr.com>
Organization: University of Geneva, Switzerland
Lines: 77

In article <7051@b11.ingr.com>, cowie@b11.ingr.com (Ivan Cowie) writes:
> In article <1782@mrsvr.UUCP>, krieg@jupiter.uucp (Andrew Krieg) writes:
>> My mouse is dying and I need to replace it fast.  Can anyone recommend one
>> of the 3rd party mice (I've seen a cordless, and another one by some company
>> ...
>> Any info on any of the above questions would be greatly appreciated.
> 
> 	Andrew, I had the very same problem with my mouse. If you have a 
> soldering iron it is easy to fix. Just open up the mouse and find the 
> little infra-red transmitters and receivers on opposite sides of the wheel.
> The problem with mine was that one of the receivers wasn't quite lined up
> correctly with the transmitter (must'v gotten jarred) so I melted the solder
> and just 'reseated' it on the board. Works fine now. Good luck!

We have 25 1040ST in house and had same problem.  Four mices went back to 
dealers,  two have been replaced, two repaired, but the repair would not last
for more than a few days.  So we decided to do it ourself, essentialy as above,
but with the following trick :  the infra-red pair are mounted on a plastic
spring, and are supposed to be adjustable with the screw at the end, but as
long it is not soldered ...  also the hole on the printedboard are metalized
which makes (un)soldering more difficult. 

So :  1.  unsolder completely the IR pair (4 wires) and pull it out of the
          printed board.  you may need special desoldering tools.

      2.  bind the 4 wires 90 degree horizontaly (carefuly !) near the diodes
          use thin wire.

      3.  solder in place 4 small wires to the board at one end, and to the
          diodes to the other end (far from the diodes)

      4.  adjust the position of the diode pair with the screw (now that it is
          free to move ...)

      5.  if you have an oscilloscope, check that the signal from the 2 diodes
          are more or less shifted 90 degrees.  At least, the cosine track
          must come up and then down before the sine one, as this is used
          by the logic to detect the direction of movement.

The mices we have repaired have been used now for quite some time and we never
had any trouble any more.   

NB: do not try to adjust the screw with the diodes soldered in place, at most
you will destroy them !    Also take the usual precautions with integrated
circuit and static electricity ... 

Here is more or less a cut through the board and diode pair.  I hope it will
help save many mices !


    > a <      |                                  |
    < d >      |                                  |
    > j <      |         (   diode pair  )        |
    < u >      |                                  |
    > s <      +----------I----------I------------+
    < t >                 I          I   <----- leads from the diodes (4)
    >   <                 I          I
    < s >     -+----------+          +----------+--      bended horizontaly !
    > c <      +------+                  +----- +        and soldered to wire
    < r >              \                /
    > e <               \              /   <---  short wire
    \_w_/                \            /
     -------------------+ | +------+ | +------------------------------ 
      ::::::::::::::::::+ | +::::::+ | +::::::::::::::::::::::::::::::
      ::::::::::::::::::+ | +::::::+ | +::::::::::::::::::::::::::::::
      ::::::::::::::::::+ | +::::::+ | +::::::( printedboard )::::::::
      ::::::::::::::::::+ | +::::::+ | +::::::::::::::::::::::::::::::
      ::::::::::::::::::+ | +::::::+ | +::::::::::::::::::::::::::::::
     -------------------+ | +------+ | +------------------------------
                       (_____)    (_____)
                          ^          ^
                          +----------+--------good soldering through the board


           God luck,    and    H a p p y    N e w    Y e a r   !

                                      Paul Bartholdi, Geneva Observatory