nms@cbnewsh.ATT.COM (n.m.scribner) (12/07/89)
There were many useful responses to my question about how to fix
a flakey C64 keyboard. In my case, the detailed instructions
from Scott Stephen (below) helped me cure the problem,
at lease for now. Thanks to everyone who responded.
I have selected and edited the pile a little.
Neal Scribner
-------------------------------------------------
article number - 1846
Path: cbnewsh!nms
From: nms@cbnewsh.ATT.COM (n.m.scribner)
Newsgroups: comp.sys.cbm
Subject: How to fix keyboard?
Message-ID: <6058@cbnewsh.ATT.COM>
Date: 23 Nov 89 05:06:35 GMT
Distribution: usa
Organization: AT&T Bell Laboratories
Lines: 8
I have a c64, vintage about 1986, whose space bar does not function
every time it is struck; frequently, it takes serveral taps to get a space.
The key does not seem to stick, or show any other obvious mechanical problem.
Has anyone had experience fixing similar problems?
Thanks,
Neal Scribner (ATT-BL, Holmdel NJ)
article number - 1848
Path: cbnewsh!att!rutgers!tut.cis.ohio-state.edu!gem.mps.ohio-state.edu!samsung!aplcen!sauder
From: sauder@aplcen.apl.jhu.edu (8908)
Newsgroups: comp.sys.cbm
Subject: Re: How to fix keyboard?
Message-ID: <4136@aplcen.apl.jhu.edu>
Date: 23 Nov 89 16:22:31 GMT
References: <6058@cbnewsh.ATT.COM>
Reply-To: sauder@aplcen (Sauder Clyde Jeffrey 688-8908)
Distribution: usa
Organization: Johns Hopkins University
Lines: 19
I once had the same vintage 64 AND the same problem. I used mine as a
word processor and really banged on the keys. In fact, I wanted a 128
so bad that when this happened, I just bought a 128. But I loaned my 64
to an Electrical Engineer friend of mine who simply pulled all they keys
off the keyboard and cleaned the contact points. Now it works great! He
said it wasn't very hard.
--
Jeff Sauder sauder@aplcen.apl.jhu.edu
article number - 1850
Path: cbnewsh!att!rutgers!usc!brutus.cs.uiuc.edu!uakari.primate.wisc.edu!caesar.cs.montana.edu!blake!milton!max!scott
From: scott@max.u.washington.edu
Newsgroups: comp.sys.cbm
Subject: Re: How to fix keyboard?
Message-ID: <10936@max.u.washington.edu>
Date: 24 Nov 89 02:17:21 GMT
References: <6058@cbnewsh.ATT.COM>
Distribution: usa,world
Organization: University of Washington, Seattle WA
Lines: 33
The problem is caused by the accumulation of dust over the years between
the contacts of the keys. Fixing the problem is simple but you need to
open the computer and requires some very simple desoldering.
To start with, remove the three screws located at the front-bottom of
the computer. (At this point, go to the bathroom or kitchen and touch
your hand to the faucet to discharge yourself of any static electricity).
After removing the screws, you will be able to open the computer up.
Now remove the keyboard cable from its socket and the "power-on" LED cable
from its socket (when removing this cable remember how it was plugged in).
Unplugging these two cables you will be able to remove the top part of
the computer from the mother-board.
When you look at the underside of the keyboard you will be able to
see two bare-wires soldered. You need to desolder these two wires from
their respective places. Having done that, now comes the fun part; you need
to remove all those little screws dotting the underside of the keyboard.
With the screws removed, you will be able to remove the underpad of the
keyboard. You need to clean this pad with a little soup and a dishwashing
cloth. You will also want to clean the underside of each key with a
glass-cleaner and cloth. Having cleaned all that, now comes the part of
putting everything back together. And hopefully after all that your keyboard.
will be more responsive.
Sincerely,
Scott K. Stephen
article number - 1853
Path: cbnewsh!att!rutgers!ucsd!sdcc6!sdcc4!ss60fhl
From: ss60fhl@sdcc4.ucsd.edu (Milo D. Cooper)
Newsgroups: comp.sys.cbm
Subject: Re: How to fix keyboard?
Summary: Clean the mother.
Message-ID: <5351@sdcc6.ucsd.edu>
Date: 25 Nov 89 23:51:56 GMT
References: <6058@cbnewsh.ATT.COM=>
Sender: news@sdcc6.ucsd.edu
Reply-To: ss60fhl@sdcc4.ucsd.edu (Milo D. Cooper)
Distribution: usa
Organization: University of California, San Diego
Open up your keyboard and clean under the spacebar with
rubbing alcohol. This worked for me for a while; but now almost
all my keys are faulty, though I've cleaned the keyboard several
times. My keyboard's just old, I guess...
--
article number - 1856
Path: cbnewsh!att!rutgers!mephisto!prism!gt4662b
From: gt4662b@prism.gatech.EDU (BRANHAM,JOSEPH FRANKLIN)
Newsgroups: comp.sys.cbm
Subject: Re: How to fix keyboard?
Message-ID: <3799@hydra.gatech.EDU>
Date: 27 Nov 89 14:51:02 GMT
References: <6058@cbnewsh.ATT.COM> <4136@aplcen.apl.jhu.edu>
Distribution: usa
Organization: Georgia Institute of Technology
I found that taking the keyboard apart and cleaning the keys didn't help much.
What I had to do was replace the rubber parts which are attatched to the
keycaps. It is a simple matter to pry the keycaps off with a screwdriver. For
replacements, Radio Shack used to sell some old Commodore 16 Keyboards for about
$3.00 each. You may still be able to find some. These are almost indentical
to a c64 keyboard, and you can rewire the matrix a bit to get it to work-though
the restore key will be missing.
--
BRANHAM,JOSEPH FRANKLIN
Georgia Institute of Technology, Atlanta Georgia, 30332
Internet: gt4662b@prism.gatech.edu
--
Steve Coan
tektronix!tekgen!stephenc
(503) 627-1794
This tends to be a problem with C64 keyboards when they get old. It's fairly
easy to fix, all you have to do is basically take apart the computer, remove
ALL the screws from the bottom of the keyboard (there's about 86,000 of them)
(slight exaggeration), clean the dust off the circuit board, then clean off the
bottoms of the keys. It should work after that. If not, write me again, I have
other suggestions, but this usually works!
-profesor@wpi.wpi.edu
---------------------
I had a similar problem on my c64, vintage 1983! (one of the first in
Australia). The main problem I had was with the 'N' key (probably from
bashing the last letter of 'run'). I had the keyboard cleaned, but that wasn't
the problem. They replaced one of the I/O chips, which fixed it perfectly.
It costs about $75, but this is Australian dollars, but pricy chips and even
worse labour charges. As an indication of differences, I bought an MPS1250
printer last year for $499, and I think the 1541 is ~$300 (I haven't bought
much for it recently).
I suggest you just take it down to a dealer, and get him to look at it. The
keyboard still works (I think - I don't use it now I have an Amiga). Try it,
and see how it goes.
Hope this helps,
Ian
--
Ian Rowlands Email : ianr@mullian.ee.mu.oz.au
Dept. of Electrical & Electronic Engineering, Melbourne University
------------------------------
article number - 1869
Path: cbnewsh!att!rutgers!mephisto!prism!gt4662b
From: gt4662b@prism.gatech.EDU (BRANHAM,JOSEPH FRANKLIN)
Newsgroups: comp.sys.cbm
Subject: Re: How to fix keyboard?
Message-ID: <3874@hydra.gatech.EDU>
Date: 29 Nov 89 03:06:40 GMT
References: <6058@cbnewsh.ATT.COM> <4803@arctic.nprdc.arpa>
Distribution: usa
Organization: Georgia Institute of Technology
Lines: 29
> I have a related problem and thought that those who read the original
> article might be able to help. My son discharged a static charge from
> his hand to the joystick of our Comm 64. after which the machine
> continually echoes spaces after boot up. Most of the keys do nothing.
> The machine is unuseable, even with cartridges that don't need the
> keyboard.
>
> There are two possibilties here. One is that the chip which deals with the
joysticks is dead (most likely). The other is that your joystick has died
in some manner and one of the switches is being held down.
I believe that the chip which drives the joysticks is located directly
next to the keyboard connector. On some C64's it is actually socketed,
and you can pull it and replace it with a new one for about $20.
(Note that there are two chips in line with the keyboard connector which
are the same type of chip. Both handle much of the C64's I/O. As an
experiment, if both are socketed, you might try switching them. If
your joystick problem goes away, but you have some problems with your
disk drive....)
Cheers-Frank Branham
--
BRANHAM,JOSEPH FRANKLIN
Georgia Institute of Technology, Atlanta Georgia, 30332
"I know my familiar is a vampire duck, just don't mess with it."
Internet: gt4662b@prism.gatech.edu
article number - 1871
Path: cbnewsh!att!rutgers!mit-eddie!mintaka!think!samsung!cs.utexas.edu!uwm.edu!csd4.csd.uwm.edu!jgreco
From: jgreco@csd4.csd.uwm.edu (Joe Greco)
Newsgroups: comp.sys.cbm
Subject: Re: How to fix keyboard?
Message-ID: <1240@uwm.edu>
Date: 29 Nov 89 03:26:36 GMT
References: <6058@cbnewsh.ATT.COM> <4803@arctic.nprdc.arpa>
Sender: news@uwm.edu
Reply-To: jgreco@csd4.csd.uwm.edu (Joe Greco)
Organization: Interstellar Telephone, Telegraph, and Telepath, Inc.
Lines: 15
In comp.sys.cbm article <4803@arctic.nprdc.arpa>, trejo@nprdc.arpa (Leonard J. Trejo) wrote:
<= stuff about joystick port zap deleted =>
>Anyone have a clue what chip or component I should look at?
The joystick ports are connected to the same CIA that the keyboard is -
"U1". It's the 6526 CIA that is right next to the keyboard connector.
Replacing it will probably run about $15 and be a snap if it is socketed.
If not, get someone who is experienced in chip removal to socket it. Not a
project for the lighthearted.
--
article number - 1893
Path: cbnewsh!att!tut.cis.ohio-state.edu!cs.utexas.edu!uunet!mnetor!tmsoft!masnet!canremote!dan.copeland
From: dan.copeland@canremote.uucp (DAN COPELAND)
Newsgroups: comp.sys.cbm
Subject: Re: How to fix keyboard?
Message-ID: <89120107511970@masnet.uucp>
Date: 30 Nov 89 02:35:00 GMT
Organization: Canada Remote Systems Limited, Mississauga, ON, Canada
Lines: 16
Take the keyboard apart (all 1Million little screws and unsolder the
shiftlock key (carefully) and clean the board contacts and the key
rubber... this will cure it for a while (my return key used to act this
way and a cleaning used to cure it) If the conductive rubber has gone
try swapping the space rubber with a seldom used key i.e. the back arrow
or the british pound key.
---
* Via ProDoor 3.1R