[comp.sys.zenith.z100] cleaning the keyboard

ddl@husc6.harvard.edu (Dan Lanciani) (07/19/90)

	What's the consensus on cleaning the key contacts?  Too many
keys are getting too unreliable and popping individual caps looks to
be potentially destructive...  Maybe dip the whole thing :)

				Dan Lanciani
				ddl@harvard.*

koziarz@halibut.nosc.mil (Walter A. Koziarz) (07/19/90)

In article <3540@husc6.harvard.edu> ddl@husc6.harvard.edu (Dan Lanciani) writes:
>
>	What's the consensus on cleaning the key contacts?  Too many
>keys are getting too unreliable and popping individual caps looks to
>be potentially destructive...  Maybe dip the whole thing :)
>
>				Dan Lanciani
>				ddl@harvard.*


Here at work I have cleaned several Z100 keyboards in the following manner.

I used a paint-spraygun connected to the building dry nitrogen line (as the
compressed air source) and filled with isopropyl (sp?) alcohol to FLUSH the
entire keyboard assembly clean.  This obviously should be performed in a well
vented area (fume hood!).

Isopropyl alcohol is harmless to the keybaord (and most other microelectronics)
and has in all the cases I've participated in solved the problem.

Walt K.

price@mandala.unl.edu (Chad Price) (07/19/90)

In <3540@husc6.harvard.edu> ddl@husc6.harvard.edu (Dan Lanciani) writes:


>	What's the consensus on cleaning the key contacts?  Too many
>keys are getting too unreliable and popping individual caps looks to
>be potentially destructive...  Maybe dip the whole thing :)

>				Dan Lanciani
>				ddl@harvard.*

from past experience, go ahead & pop the keys (carefully). I would however be
reluctant to remove the space bar, as I did once & had real problems putting
it back on. BTW it was on an IBM AT keyboard - one of the originals.

Some of my friends have also disassembled the keyboard on an Apollo (3500) &
put it back together with no ill effects except that it works better now. 

Chad Price
price@fergvax.unl.edu

sampson@cod.NOSC.MIL (Charles H. Sampson) (07/19/90)

In article <3540@husc6.harvard.edu> ddl@husc6.harvard.edu (Dan Lanciani) writes:

>	What's the consensus on cleaning the key contacts?  Too many
>keys are getting too unreliable and popping individual caps looks to
>be potentially destructive...  Maybe dip the whole thing :)

     I must have missed something here.  I've replaced a number of keys on
my Z-100 keyboard (we are talking about Z-100s, aren't we?), with such nasty
side-effects as breaking a trace and having to solder a jumper on the back
to fix it.  The reason for all of this is that the key units on my keyboard
are virtually sealed.  When the keys started acting up contact cleaner had
no effect.  I assumed that it was because not enough cleaner could get into
the units and what could just dribbled down the sides of the shaft and ended
up in a useless location.

     Popping the caps was no problem, by the way.  Except for the space bar,
which was a real bear to reassemble, as another respondent has already noted.

                               Charlie Sampson

zateslo@geomag.fsu.edu (Ted Zateslo) (07/19/90)

We have successfully used TF solvent (available at electronics jobbers,
etc) to clean Z-100 and other keyboards.  You can often fix an 
individual stubborn key by squirting the stuff between keycaps and
depressing the key repeatedly.

WARNING: do NOT use a product called "Blue Shower" on keyboards.  Even
though the label claims it won't hurt electronic things, it dissolved
the protective coating from a Z-158 keyboard we were cleaning; the
gunk lodged in the keyswitches and we were out one keyboard.  The TF
sovent, though, never seems to hurt anything.

-Ted Zateslo, FSU Geology Dept.
Internet: zateslo@scri1.scri.fsu.edu

fzsitvay@techbook.com (Frank Zsitvay) (07/23/90)

In article <2521@nosc.NOSC.MIL> koziarz@halibut.nosc.mil.UUCP (Walter A. Koziarz) writes:
>In article <3540@husc6.harvard.edu> ddl@husc6.harvard.edu (Dan Lanciani) writes:
>>
>>	What's the consensus on cleaning the key contacts?  Too many
>>keys are getting too unreliable and popping individual caps looks to
>>be potentially destructive...  Maybe dip the whole thing :)
>>
>>				Dan Lanciani
>>				ddl@harvard.*
>
>
>Here at work I have cleaned several Z100 keyboards in the following manner.
>
>I used a paint-spraygun connected to the building dry nitrogen line (as the
>compressed air source) and filled with isopropyl (sp?) alcohol to FLUSH the
>entire keyboard assembly clean.  This obviously should be performed in a well
>vented area (fume hood!).
>
>Isopropyl alcohol is harmless to the keybaord (and most other microelectronics)
>and has in all the cases I've participated in solved the problem.
>
>Walt K.

   what also works very well is to take the keyboard out of it's case, and
put it in your dishwasher, along with your favorite dishwashing detergent.
Cascade works fine for me.
 
   this is no joke.   we have used this technique on circuit boards and
keyboards extensively, and it works very well and does not damage the board
at all.
 
   things to watch for...  most dishwashers have a heating element on the
bottom of the unit, make sure the keyboard is nowhere near this.  putting it
on the top rack should be fine, but make sure it isn't in the path of a high
pressure stream, either.  after washing the board, leave it in the open air
to dry.  don't let it go through the "dry" cycle of the dishwasher, since this
could melt it.
 
   and of course, don't use "jet dry" or other water additives outside of what
is in the detergent.  "jet dry" leaves a film on circuit boards that can be
a headache to remove.  it's not conductive, but it's not the most desirable
thing either.


-- 
fzsitvay@techbook.COM - one of these days i'll get it right...

Version 2 of anything is usually the version that works.

ruderman@sboslab7.cs.sunysb.edu (David Ruderman) (07/23/90)

In article <3540@husc6.harvard.edu> ddl@husc6.harvard.edu (Dan Lanciani) writes:
>
>	What's the consensus on cleaning the key contacts?  Too many
>keys are getting too unreliable and popping individual caps looks to
>be potentially destructive...  Maybe dip the whole thing :)
>

	It has been my experience (with the H/Z-120 all-in-one)
that if the keys
do not clean by opening up the machine and blowing out the keys
with some high powered contact cleaner, then you can replace the 
keyboard which just pops out (after you dig down into the machine and 
find some money) or replace the individual key switch (which can be had
from heath/zenith quite cheaply, if they got them.  I suggest you get
a dozen. You have to take out the keyboard, desolder the switch, then
remove it.  The new switch just pops in.)

	I had to resort to replacing the keys, because the spraying
just clogged up the key switches more (and other adjacent keys).  In fact
I have also replaced the keyboard (at the time they were $120 with a 
trade in.)

	I havent done this in some time, but my poor friend who now
owns the machine has to do this occasionally.

-dave
--
--------------------------        -   
David Ruderman                  ( # ) O '  '   '    '     '      '       '
Racquetball Commissioner          Y      Racquetball
--------------------------        I           Uber Alles!

mic@sun.soe.clarkson.edu (Mic Lacey) (07/24/90)

	I got my machine in 83 and my keyboard has had occasional trouble 
since 87 (once or twice a year a key will stop working).  I have had a lot 
of luck with WD 40 (give me a can of WD 40 and a pair of vice grips and 
I can fix anything).  BTW I offer no warranty on this advice :)

	-Mic