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From: DAVISM@kcgl1.eng.ohio-state.edu (Michael T. Davis)
Newsgroups: comp.sys.atari.8bit
Subject: Re: Flakey 130XE keyboard
Message-ID: <5607@quanta.eng.ohio-state.edu>
Date: 23 Aug 90 04:05:28 GMT
References: <306@sherpa.UUCP>
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In article <306@sherpa.UUCP>, rac@sherpa.UUCP (Roger Cornelius) writes:

>A friend has a 130XE with a flakey keyboard.  The symptoms are:
>
>Anywhere from 5 - 15 minutes after powering on, the keyboard stops
>working, but not completely.  You just have to press very hard to get
>the keys to register.
>
>Powering off then back on has no effect if the power-on is immediate.
>The unit must remain off for awhile to have any effact.
>
>This sounds sorta like a heat problem and sorta like a mechanical
>problem.  Does anyone have any suggestions for him.
>
	It sounds like you are slowly frying your keyboard.  When I had my
130XE, I too went crazy trying to figure out what was wrong.  First step...
open your computer (warranty -- we don't need no stinking warranty ;-).  Care-
fully pull the "ribbon" from the keyboard connection on the motherboard.  Clean
the runs with a soft cloth (e.g. paper towel) with a solution of mild soap and
water.  (I used Ivory dish washing liquid.)  Rinse the runs and dry them.  Now
find R95 on the motherboard (somewhere near the keyboard connector).  In some
models, Atari in its infinite wisdom (yeah, right :-) chose to use a resistor
of smaller value than really required.  Thus more current gets through than
should normally be allowed through runs of conductive paint.  Unfortunately, I
don't remember the value of the resistor I used to replace R95.  Try 1K and
see what happens.  You want something at least twice the resistance of the
existing resistor (220 Ohms), but not so strong that you can no longer see the
power LED.
>Thanks.
>
							Good luck,
							   Mike
>--
>Roger A. Cornelius          rac@sherpa.UUCP         uunet!sherpa!rac

    davism@kcgl1.eng.ohio-state.edu    |      These Thoughts, They Be Mine
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