[sci.electronics] remote control buttons

tolboel@iesd.auc.dk (Morten Tolboel) (07/10/90)

Many IR remote controls have rubber buttons which have some kind
of conducting material on the backside of them. When a button is
pressed this conducting material is pressed onto the pcb to make
a contact.

Does anybody know what this conducting material is ? (some kind
of carbon or what?) Many of the buttons on my SONY remote control
does not work very well anymore and I have been told that this
is a common problem (at least for SONY IRs). I could get replacement
buttons for my remotecontrol (~ $30) but I would like to know if
somebody has any experience how to replace the old conducting
layer on the backside of the buttons. 

Morten Tolboel
e-mail tolboel@iesd.auc.dk

jim@ghp.UUCP (Jim Stewart) (07/11/90)

In article <TOLBOEL.90Jul10101202@dirac.iesd.auc.dk> tolboel@iesd.auc.dk (Morten Tolboel) writes:
>
>Many IR remote controls have rubber buttons which have some kind
>of conducting material on the backside of them...

>	...I could get replacement
>buttons for my remotecontrol (~ $30) but I would like to know if
>somebody has any experience how to replace the old conducting
>layer on the backside of the buttons. 

I think I have the same on the keypad to my handheld radio.
I had some luck just taking it appart (carefully, lots of springs, etc.)
and just cleaning the contacts.  It eventually returned to worse
than the original state, but that was 1.5 years later.  I just
repeated the exercise.

good luck

-- 
Jim Stewart, VE3SRJ
UUCP:  jim%ghp@mnetor.uucp
BELL:  (416)862-0430

scheer@motcid.UUCP (Jon Scheer) (07/12/90)

   Sorry I can't answer your question directly, but a friend and myself
managed to resurrect a remote that had 'worn' buttons.  We were in a
rush, so it was a quick-and-dirty fix, but it worked.

   We took an antistatic bag (since it was conductive) and cut one side
(layer) of it to the shape and size of the remotes button pad.  We then
sandwiched the piece between the pad and the pc board and reassembled the
remote.  The buttons would then push the layer against the pc board, closing
the contacts.

   It worked good.  Almost too good.  It was sensitive enough that if
you simply shook the remote, sometimes it would misfire...  :)


Jon
7/11/90
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stroh@ssc-vax.UUCP (Steven K Stroh) (07/14/90)

Many devices that use conductive rubber buttons start having 
intermittant operation after a few years because of the
general dirt and other blech that seeps in around the edges.
In a former life I was sentenced (:-) to work for a well known
videogame manufacturer, and the cure for the great majority of
the handheld controllers was a simple scrubbing of the contacts
on the PC board with an ordinary pencil eraser.  It doesn't
hurt to clean the BUTTONS with isopropyl alcohol.  DO NOT use
the alcohol on the PC board- it's quite likely that you'll damage
the contacts (which are not bare copper, but treated to work
well with the button material).


Steve Stroh