AMIGA 1200 KEYBOARD MEMBRANE REPLACEMENT PCB (FFC VERSION)

(MITSUMI 56C774A A-1200A REPLACEMENT)

Layers : 2 Layers PCB

Material : FR-4

Thickness : 0.6 mm

Surface Finish : Immersion gold (ENIG)

Note:The PCB thickness must be 0.6mm, please pay attention to and double check the thickness of the PCB you choose.

Hello,

After sharing a PCB membrane replacement for Amiga 500 some of my friends asked me to make a similar PCB membrane for Amiga 1200. But I do not have an A1200. My friend Orhan gave me an A1200 keyboard to use for this project. I drew the membrane and my another friend Turgay ordered PCBs and tested. He aproved the GERBERs are OK and PCBs worked as they should. (Many thanks to Orhan and Turgay)

I designed the A1200 membrane and headers in two versions. One version is IDC version the other version is FFC version. IDC version is through-hole technology (THT), FFC version is surface mounted technology (SMT). IDC version membrane must be used with IDC Header and FFC version membrane must be used with FFC Header.

Both IDC and FFC versions consist of 3 main parts.

1) Keyboard membrane PCB - Thickness : 0.6 mm Surface Finish : Immersion gold (ENIG)

2) Header PCB

3) Cable between header PCB and keyboard membrane PCB

The most important difference between IDC and FFC versions is; the IDC version membrane connector must be soldered after being placed on the metal housing of the Amiga 1200 keyboard. In the IDC version, once the connector has been soldered, the connector have to be desoldered so that the PCB membrane can be separated from the metal part. For this reason, it is not possible to sell the IDC version membrane as a complete ready to use. But FFC version can be sold as ready to use.

Make sure your keyboard membrane is defective before ordering this PCB. Sometimes the problem is the conductive rubbers under the keys, and you can easily fix this with a soft 4B pencil. You only need to completely scribble the conductive rubber itself and the membrane's pads with a 4B pencil.

If you are using a 1mm thick Header PCB, you have to remove the clamping part of the keyboard connector on the motherboard. (My friend Turgay said he thinks 1mm thickness is better than 0.6mm thickness for header PCB.)

If you are using a 0.6mm thick Header PCB, with the A1200 motherboard keyboard connector locking system in the unlocked position, gently push the PCB into the connector. You may need to shake the PCB a little if it's having trouble getting in. Next, close the lock of the connector by pushing it slowly.

If there are keys that do not work, clean all the contacts on the PCB (including connector part) and the conductive rubber contacts under the keys. You can use a sand eraser or an ink eraser to clean the PCB pads. And you can scribble the PCB pads with a 4B pencil to increase conductivity.

Do not rush and be careful while following these procedures, ask for help from a knowledgeable person at a point you need asistance.

For testing Amiga keyboard, you can download the "Amiga Test Kit" ADF disk image from this link.

https://github.com/keirf/Amiga-Stuff . Many thanks to Keir Fraser (keirf)

Components:

2pcs. 32 pin 1mm Pitch FFC FPC Connector (one for the header PCB and the other for the membrane PCB)

10cm, Same Side Contact, 1mm Pitch, 32pin, (FFC) Flat flexible cable

HEADER PCB (FFC VERSION)

Gerber files and component list are subject to change without notice. Before paying for the PCBs, be sure to update your orders!

As you can see I have uploaded many projects and I am still working on new projects. If you have any questions, please look for answers online. Unless I specify explicitly, all my projects are tested and confirmed to work under normal circumstances before being shared. I'm sorry I didn't have enough time to answer all the questions.

Use this PCB at your own risk !

Have fun

Thank you.

C64istanbul