AWKSG%UOTTAWA@ACADVM1.UOTTAWA.CA (Alan Kelm) (03/13/91)
The following tidbits may be of interest for those of you who are
experiencing problems with the buttons on your Amiga mouse.
My left mouse button was giving the same problems that many others
have reported; namely that a click did not always register, and
sometimes a single click registered twice.
Opening the mouse (using the two screws on the bottom) and popping off
its top, one notices that beneath the mouse buttons are two small
switches that look like the following:
----------
1---| __ |---3
| / \ | (four legs... the circle in the center is a button)
| | | |
| \/ |
2---|________|---4
A roommate who happens to be an electronics technician explained to me that
this package actually contains TWO switches: one between legs 1 and 2, and
the other between legs 3 and 4. If you flip over the PCB (you have to
undo two black screws near the ball of the mouse to do this), you will notice
that the circuit makes use of only one of the switches, say the one between
legs 3 and 4. As my friend explained, every time the switch is pressed, a
small arc occurs within the switch, and eventually causes a build-up of a
deposit of carbon or something, which makes the switch unreliable.
The good news is that since pins 1 and 2 are unused on the PCB, there was
never any arcing taking place on that switch, so it is as clean as new.
The FIX which my roommate did is the following:
(1) Unsolder the switch's four legs
(2) Rotate the switch 180 degrees.
(3) Solder it in place again.
The effect of this is to place the UNUSED switch (between pins 1 and 2)
in the position where the worn out switch was. We did this, and now my
mouse button works fine.
This "Fix" essentially doubles the life of your mouse buttons. Of course
once you have worn out both switches in the button, the button must be
replaced.
Other tidbits:
We found that the old Amiga mice contain small button switches, about
6 millimeters square (1/4 inch). The new Amiga mice contain larger
button switches, measuring about 11 millimeters (1/2 inch) square.
As pointed out by someone else on the net, the larger switches can
be ordered from Digi-Key Corporation:
Phone: 1-800-344-4539, Fax: 1-218-681-3380.
The part is called a
Panasonic Momentary pushbutton switch Part # P9950, and they cost
45 cents each.
I ordered 20 of them, and got them for 37.7 cents each. However there
was a $5 handling charge ('cause it was a small order) and another $5
handling charge because I live in Canada.
If you happen to have a fried switch in your mouse and the first fix
I mentioned (180 degree rotation) doesn't work for you, and your buttons
are of the 11 millimeter variety, drop me an EMail message
with your postal address, and I will put a switch in the mail for you
(I don't know what else to do with 20 mouse button switches).
First come first serve. (If you don't get an EMail acknowledgement within
a couple days of your request, send it again... our mail connection may
be flakey).
I hope this helps.
- Alan Kelm, Department of Mathematics, University of Ottawa.
EMail: awksg@Acadvm1.UOttawa.CA
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