Refurbishing a ZX Spectrum 128 +2B keyboard
When I fixed the ZX Spectrum 128 +2B machine I simply replaced the non-working keyboard with a known to be working keyboard. If should be fairly straightforward to get this keyboard working again.
Cleaning the parts
The keyboard needed a good cleaning, it looked like it has never been cleaned it all the years of its existence. To make it easier to clean it I took the keyboard completely apart. This makes it much easier to soak all of the plastic parts in lukewarm water with a bit of detergent. This got rid of most of the dirt, the rest of it cloud be removed using some wet hygienic cleaning-tissues (for instance Dettol). They keys themselves also contain a little metal spring, so I simply used my heat-gun (you can also use a hair-dryer if you don’t have a heat-gun) to remove any water droplets inside the springs as to prevent any future corrosion. Be careful not to overheat the keys, otherwise you run the risk of deforming the keys.
![Parts before cleaning](/_image_cache/97dfa17a-bd60-469d-b1ac-49280c658e6c.png)
![Parts after cleaning](/_image_cache/1da6f460-c6ef-4d4e-b005-4cdfbb42e0ac.png)
After cleaning these parts most of the keyboard can be put back together again. I wasn’t paying attention when I inserted the keys and springs into the key-housing, so I had troubles putting the last key back into key-housing. The spring I was left with did not fit other the cylinder, it was too small. I hadn’t noticed that for the Enter a smaller spring is used.
![Two sizes of springs are used within the keyboard](/_image_cache/59bbd212-2b43-4131-86a8-9e40902c2559.png)
I was fortune that I could determine this by just examining the back of the key-housing, preventing me from having to remove all of the keys again and start over.
![Back off key-housing and spotting the size difference springs](/_image_cache/0c5fd4f0-7aa3-4f6b-bc96-3d1a7631498a.png)
Clean and test the keyboard membrane
The keyboard membrane itself was a bit dirty as well. Since this part is the most fragile part of the keyboard I just gave it a good dusting, especially the ends of the flat-cable connectors. To test the keyboard membrane without having to fully assemble the rest of the keyboard I gently inserted the flat-cables into the appropriate molex connectors on the motherboard of the ZX Spectrum 128 +2B. After turning on the machine carefully test several connectors by compressing a node between your thumb and forefinger. I my case the ones I tested were working .
Now that the keyboard membrane appears to be working the rest of the keyboard can be assembled and I could properly test all of the keys.
Job done
A fully cleaned and working spare Keyboard for the ZX Spectrum +2A/+2B
![Refurbished keyboard for a ZX Spectrum +2A/+2B](/_image_cache/ebc9c403-9550-4022-9f9b-068f7c184c38.png)