View Full Version : Keytronic capacitive keyboard repair...disaster

December 16th, 2013, 03:19 PM
Hi all,
Just wondering if anyone could help me solve my keyboard repair issues.
I have a Franklin Ace keyboard that I use with my Orbtronix Apple 1. It uses the capacitive Keytronic keys, and the foam had died.
I purchased some foam pads from ebay (just the foam pads), a mylar space blanket, and an 11mm punch. I reused the plastic disks from the old dead foam pads.

Last night I finally had time to attempt the repair. It took maybe more than 4 hours in total. I took my time and I think I did a fairly good job.
After I re-assembled the keyboard the results were disastrous.
Basically about 90% of the keys seem to have issues. For example when I push the 'A' key, something like this appears on the screen 'BCAS-S'...but obviously it's not the same every time. Some keys work better than others, and some keys almost work perfectly. I also get debounce often.

I basically followed the instructions here, and I put the conductive side of the mylar face down so that it makes the contact:

Anyway, just wondering if anyone has any insights.


December 16th, 2013, 03:28 PM
Try it with the non-conductive side down? Have a couple of keyboards here myself that need 'the treatment'...

December 16th, 2013, 03:43 PM
Humm, unfortunately that means redoing everything again. Oh no!!! Not looking forward to another 4+hours.
I'll do a tests.



December 16th, 2013, 03:58 PM
I did a couple of Lisa keyboards and the mylar needed to be non-conductive.

December 16th, 2013, 04:12 PM
Oh...that totally sucks. What a waste of time and money.
Maybe I should let Geoff Harrison know that his instructions are incorrect.

December 16th, 2013, 04:39 PM
Sorry to be the bearer of bad new but if that's your only issue, you are lucky. I used shiny mylar birthday wrapping paper and nether side was conductive, actually. I was shocked that it worked. Please don't ask me how or why.

Think of the bright side. At least you now have practice and you'll be a little faster this time :) Good luck.

December 16th, 2013, 05:51 PM
Just buy a Sun model 4 keyboard, you can find them on the web already refurbed. These keyboards have the plastic/foam/Mylar discs in them. I have used them on trs-80 model 12 keyboards, and northstar advantage keyboards. Both now work great. No other Sun keyboard has the foam discs, so don't buy a model 5,6 or 7.


December 16th, 2013, 06:15 PM
Oh...that totally sucks. What a wast of time and money.
Maybe I should let Geoff Harrison know that his instructions are incorrect.Try it first. Shouldn't be too bad; punch out a few disks to test and just stick them on top of (underneath?) the existing ones with spray adhesive or double-sided scotch tape (before punching).

December 16th, 2013, 06:47 PM
Ha, you read my mind. What I have done is to glue all the pads to a the correct side of the mylar. I will then use the 11mm punch that slides over the pads perfectly, and then re-punch them all out again. I've already tested it with about 6 pads and that work perfectly in the keyboard. This certainly saves a lot of time and money...It's not perfect, and I'm a bit of a perfectionist, but it'll have to do.


I'll let you know how it turns out when I'm all done.

Thanks for all the advice.


December 17th, 2013, 03:54 AM
Finally all fixed. Thanks to you all for your advice.

December 17th, 2013, 01:57 PM
FYI here are the pads I used. They seem to work very well.