The Amiga line of computers from Commodore are getting older by the day and their parts need maintenance to function properly. The keyboards are no exception. In this post I write about my experiences of making my Amiga 600 keyboard working again. The problem I had was that some of the keys did not work. There was no logic to which keys were functional and not either.
First of all, I noticed that the membrane of the keyboard was worn. I order a new membrane from Amigastore.eu. This, however, did not solve the problem. The very same keys still did not work. I short circuited the connection points on the membrane under the non-functional keys, and the membrane checked out ok. Hence, the problem seemed to reside in the keys themselves.
So, let’s take a look at how a key at the Amiga keyboard is constituted. Under the key, there is a spring mechanism that presses on a black conductive pad when you press it. This pad short-circuits two connections on the membrane, signaling to your Amiga that the key is pressed. Consulting a friend, he suggested that these conductive pads stop being conductive over time.
Your first task is to disassemble the A600 keyboard, and this is easy enough. After opening your A600, gently lift the top of the white keyboard connector and lift the keyboard. Then, use a small Philips screwdriver to remove all the tiny screws from underneath the metal plate of the keyboard.
Making the pads conductive again
Now, there are a few solutions to the problem:
- Replace the pads with conductive pads from another Amiga / Mitsumi keyboard.
- Paint the pads with conductive ink.
- Glue copper tape under the pads.
I opted for solution no. 3 as I had a roll of copper tape at home. I first tried it on a couple of keys, and it worked out just fine. While my tape is self-adhesive, it was not enough to make it stick to the rubber pads though. So, I used universal glue (Swedish “Karlssons klister”) to secure the tape in place under the pads:
- I cut a cotton bud in half and dipped the non-cotton part (the stick) in glue. Any little stick will do though.
- I then carefully “brushed” the glue to the undeside of the pad.
- Then, I cut a suitable piece of copper tape and separated it from the film it was attached to, and firmly pressed it to the glue on the pad.
- I repeated steps 1-3 for all non-functional pads, waited for the glue to dry, and viola! They all now work properly!
The keys with copper tape under them actually work better than the other keys, suggesting that eventually all keys should be subject to the same treatment.