Servicing Amstrad 2000 Series Keyboards

Amstrads 2000 series of PCs had a proprietry keyboard interface which makes it impossible to use a standard IBM PC-XT or PC-AT keyboard. Should the keyboard fail in any way, the system cannot be booted and stop at the BIOS displaying 'check keyboard', accompanied by continuous beeping.

 

Dissassembly

The keyboards can be easily dissembled without tools, since the top and bottom casings are held together with spring clips freely accessible on the base:
With the case opened, the inner keyboard can be seperated from the circuitry by gently pulling out the two ribbon cable edge connectors from the socket. Extreme care should be taken not to rip the cables:
The inner keyboard can then be opened by releasing the plastic clips along the back:


Servicing

Cleaning

After many years of use and storage, a fair amount of dirt can accumulate within the unit. Most can be simply brushed away, and the plastic key pressure sheets then cleaned by gently wiping over both sides with a soft cloth and isopropynol.

If the outer plastic is discoloured, this can be removed by rubbing gently with white vinegar.


LEDs

The LEDs for caps-lock, scroll-lock and num-lock seem crtitical to the operation of the keyboards. Instead of being soldered, the LED leads are bent around and pressed into small silicon formers:
Once correctly lined up, contacts on the plastic pressure sheets then form the connections.


Connectors

The ribbon edge connectors should also be cleaned by wiping with isopropynol. A fair amount of oxidation had gathered on the unit pictured, which was however easily wiped away.


Reassembly

Reassembly is very straightforward since everything just clips back together. Be sure that the pressure sheets are correctly aligned and not trapped before snapping the inner keyboard back together.

The ribbon edge connectors simply push back into the sockets, starting with the upper connector: