c64c: possible to improve keyboard contacts?

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c64c: possible to improve keyboard contacts?

Postby Matt on Tue Dec 02, 2014 7:05 am

My c64c goes now. I had decided not to try the vic20 psu since it's a different part no. and amp rating
then I saw a thread here implying the 64 and v20 psus were equivalent so I gave it a shot.
I can get almost every character but on several keys this involves holding down with extreme
pressure for a sometimes 2s or longer. Any way to fix this?
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Re: c64c: possible to improve keyboard contacts?

Postby Clym5 on Tue Dec 02, 2014 7:32 am

I had this issue with a few of my 64's too. (and a BBC) It seemed to be that if the unit hadn't been used in a very long time, the worse the keys were.

I fixed all of mine with a once over with compressed air, and button-mashing the key. Not hard, just intensely. Usually fixed it after a few minutes on each key.
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Re: c64c: possible to improve keyboard contacts?

Postby Matt on Sat Dec 27, 2014 8:10 am

clym5:
>>>fixed all of mine with a once over with compressed air, and button-mashing the key

I had to go a little further with mine. Completely dismantled the keyboard unit,
wiped down the contact side of the backboard, plucked all the rubber strips like
guitar strings, borrowed the strip from 'Q' and pressed it on the contacts - all
working. Reassembled and now it works. No idea why it should work after that and
not before - didn't seem like I had changed much. Due to lack of appropriate tools
and not as much patience as I'd like there was collateral damage: shift-lock is now
permanently on, and no 'Q' because the end of the rubber strip broke off when I
removed it. A vast improvement overall though - before I had no space or return so at
least now I can play around with basic.

Does anyone know how to replace the top cover (64c, not breadbin)? I can get it
clipped on at the back and sides but I can never get it to sit flush above the middle
screw at the front.
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Re: c64c: possible to improve keyboard contacts?

Postby tezza on Sun Dec 28, 2014 7:26 am

Matt wrote:Does anyone know how to replace the top cover (64c, not breadbin)? I can get it
clipped on at the back and sides but I can never get it to sit flush above the middle
screw at the front.

Hmm. Strange it doesn't line up. I've taken mine apart and can't recall having a problem reassembling, or there being anything tricky about it? It was a long time ago though :) . I might have forgotten if any particular technique was required.
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Re: c64c: possible to improve keyboard contacts?

Postby Gibsaw on Mon Dec 29, 2014 11:04 am

Image
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Re: c64c: possible to improve keyboard contacts?

Postby Clym5 on Mon Dec 29, 2014 2:11 pm

I love that post. The "Apple II's are my thing" under it just makes it funnier.

I just took apart my 64C, and it sits perfectly. Are there any cables in the way? Bent plastic?
Amiga 4000: Apollo Turbo 040, 128MB Fast, 40gb HDD, CD-ROM (needs internet)
C64: 1541U-II, MixSID, WiFi, LumaFix64
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Re: c64c: possible to improve keyboard contacts?

Postby LilJoe on Mon Dec 29, 2014 8:14 pm

I found it harder to take mine apart than to put it together :? maybe the plastic has slowly moved and bent over time. If you don't mind de-authenticating it you could always drill new holes... :D
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Re: c64c: possible to improve keyboard contacts?

Postby Clym5 on Mon Dec 29, 2014 8:58 pm

My breadbin doesn't have screws in it anymore, and I haven't found that too be much of an issue. The one thing that does get irritating, is the little hooks at the back of the case. They're a really bad fit, and like to push the plastic out at the back. It needs 30 seconds of careful movement, but that's it.
Amiga 4000: Apollo Turbo 040, 128MB Fast, 40gb HDD, CD-ROM (needs internet)
C64: 1541U-II, MixSID, WiFi, LumaFix64
ZX Spec, A1200, CD32, MacPlus/SE, A500, BBC Turbo Master (NASA), 2600, Acorn 4000, VIC-20, IBM 5155, GameBoy
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Re: c64c: possible to improve keyboard contacts?

Postby kevman3d on Tue Dec 30, 2014 6:07 pm

Matt wrote:No idea why it should work after that and not before - didn't seem like I had changed much.


I think you said you cleaned the contacts - it doesn't take much to cause those to have issues as I found with my old Dk'tronics, just a little clean usually fixes most of those old-style keyboards (crap builds up on the contacts over time, but they can also wear away (if you're heavy-fingered). But its good to hear you managed to fix it nonetheless... :)

and no 'Q' because the end of the rubber strip broke off when I removed it.


Do you mean the peg that sits under the key? (this thing) If so, let me know... I can send you one if you need it (just PM me a postal address) - pretty sure I know where I put the spare one or two - somewhere in the room. :mrgreen:

clym5 wrote:The one thing that does get irritating, is the little hooks at the back of the case. They're a really bad fit, and like to push the plastic out at the back. It needs 30 seconds of careful movement, but that's it.


lol! Yup - I know what you mean! When I opened up the C64 here I scratched my head why it wouldn't open, then the click when it unclipped made me think I'd broken it somehow.
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Re: c64c: possible to improve keyboard contacts?

Postby Matt on Wed Dec 31, 2014 8:54 am

tezza:
>>>Hmm. Strange it doesn't line up

clym5:
>>>took apart my 64C, and it sits perfectly

That will be because you both replaced the black plastic keyboard housing *under*
those 3 plastic bits, where it is meant to go. I've said here before I'm more of a software guy lol.

kevman3d:
>>>Do you mean the peg that sits under the key? (this thing) If so, let me know... I can send you one if you need it

Yep that's the thing. I didn't disassemble to that degree though with hindsight it'd have been better if I had.
I just saw the rubber strip there and grabbed it out to press down on the contacts for testing.

>>>If so, let me know... I can send you one if you need it

Thanks. Might do that in a wee while. For now I need to learn to solder, build the x1541 cable etc. Theres no 'q'
in load anyway so for now it's not a biggy since I'll be cross developing on the pc with cc65 - first things first:
Hello world!

>>> >>>Matt wrote:No idea why it should work after that and not before - didn't seem like I had changed much.

>>>I think you said you cleaned the contacts

Isn't the actual electrical contact taking place somewhere under the surface though with the two bits of the
rubber just providing physical pressure?
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Re: c64c: possible to improve keyboard contacts?

Postby kevman3d on Thu Jan 01, 2015 12:44 pm

In case its of interest (given you've already opened it anyway, maybe there's something here that might be useful) this page has a very nice article about opening and cleaning the C64 keyboard (plus talks about opening the case too). :)

http://www.bjtechserv.com/Magazine/C64/C64_Keyboard_Clean.htm
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