Replacing A1200 Keyboard membrane (guide)

[rabidgerry]

Hello all,

just thought I'd document my latest A1200 modification where I replace my old keyboard membrane with a brand new one.

I could have fixed the ribbon cable on the old one, but I couldn't be arsed messing about with peeling plastic and scraping away to allow for better contact etc so despite that membrane actually being ok it's the ribbon cable end that needs a fixing. I might flog it on ebay or something for someone who can repair them.

Anyways here goes.


First remove the keyboard from the Amiga 1200. Done this a million times myself. Then start to unscrew all the little screws from the metal backplate.



Once all screws have been removed gently lift the back plate off and expose the old membrane.



Remove the backplate completely and leave the membrane exposed.



With the membrane removed you will expose all the little key plungers. I hoovered and cleaned this meticulously one I removed the membrane.



On the recommendation of the new membrane instructions, I cleaned every plunger with IPA. Seemed unnecessary to me to do so as it looked clean but I did it anyways.





Behold, the new membrane and crazy long detachable ribbon cable



Take the new membrane and again according to the instructions that came with it, use the supplied alcohol wipe to clean the new membrane. I think this is a "just in case" measure as the new membrane look spotless and finger print free to me.



Once cleaned take your keys base, lay it flat with keys facing down, then lay the new membrane on top. In my case this membranes black side goes face down on the key base.



Match the membrane holes to the little guide pillars that are on the keybase.



They should poke through the matching holes on the membrane



Then take your backplate and also match it's holes up with the little little pillars on the keybase.



With my new membrane it has a little lip for the ribbon cable, this pokes through the same slot in the keyboard backplate as the old membrane ribbon cable was originally fed through. On the top right hand side of this pic you can see the lip poking through.



Something I never thought off, but was in the new membrance instructions. Basically hold the keyboard assembley together firmly and place it back into your Amiga 1200 BEFORE you screw the backplate back on. This is so we can test it out before screwing all those screws back in again.



Ribbon cable which is detachable at the keyboard side. Makes it handy for removing the keyboard in future as opposed to undoing it from the motherboard side.



The grey connector slips onto that lip I mentioned from earlier from the new membrane. Be sure to get the orientation right. Just look at how I did it in the photo.




After you connect the cable to the membrane,

then connect the other end of it to the mother board just like the original one using the little slot clamp that you feed the ribbon into, hold into place then bring the clamp back down again.



With the keyboard now fitted, power your Amiga on and open Amiga Test Kit or other keyboard testing software.



Go through all the keys to make sure you are getting a response nice and quickly.



All good for me as you can see.



After testing, power down your Amiga, remove the keyboard assembly again holding together with your fingers. I perforated the gold foil on my membrane to allow the screw holes to go back in more easily. But basically at this stage we are going to be putting the screws back in.



Screwing the screws back in again. Don't do them to tightly btw.



All back in. Now fit the keyboard back into your A1200 as you would normally.



It's a really long ribbon cable which will need tucking in once the Amiga case goes on again. See how I have gently nudged the excess from the cable under my IDE which acts as a nice little holder.



Ok hopefully this is of some use to somebody. I never done this before but it all went smoothly. It is a fairly straight forward modification/upgrade to make and the performance of the new membrane is excellent.

[crazyc]

Far more thorough then when I did mine!

[rabidgerry]

Originally Posted by crazyc

Far more thorough then when I did mine!

Yeah, not very often I am as thorough but I decided to do it all by the book this time.