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I recently powered on my 48k ZX Spectrum (1983 Issue 3B), and the keys 1-5 were not working. I decided to open it up to see if reseating the keyboard connectors would solve the problem. Unfortunately in doing so I snapped one of the connectors, and the other fragmented as I was trying to remove it.

I understand that the next step is to get a new, modern membrane, but before I can fit it, I am going to need to get the end of the broken one out. I have tried tweezers, but was not able to grip well enough to pull it, and a toothpick but was unable to loosen it. How can I go about removing this end of cable without further damaging the machine?

Broken end of keyboard cable stuck

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    This will be a struggle. The first option would be to find a tool that can grip the remaining part of the ribbon and pull it out. Failing that you might try gluing something to the ribbon fragment using cyanoacrylate (super glue). Use a tint trace of adhesive but get a large area of contact if possible and allow a few hours for the bond to reach full strength, even though it may seem to have set after 10 seconds. As a third option you could try to stick the end of a sharp blade into the ribbon and lever it against the edge of the connector body. If you can get any movement… Commented Aug 8 at 10:11
  • …try in a few different places Commented Aug 8 at 10:11
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    @Frog, trouble is, you put glue near that fragment of strip and even a little glue could go into the connector. It's just not worth the risk. Commented Aug 8 at 19:03
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    I might have replaced the connector while already in there. It might be as crummy as the membrane. If you do, then the problem is solved! Commented Aug 8 at 21:34

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I'd use a pair of flat fine-nose pliers to pull it out.

First though, I'd spray a little switch cleaner, such as Servisol, into the connector and let it soak into any corrosion in there for a while.

Then I would gently flex each contact slightly using a jeweller's screwdriver. Those contacts have got to flex now to get this out and flex later to get the new ribbon in, so they're not doing anything they won't be doing sometime anyway.

Then I'd try pulling it out with the aforementioned pliers (this sort of thing).

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    @tofro, "this sort of thing" though. (For mine, we paid £30 in 1990s. Used for soldering through-hole, been brilliant and lasted so £64 today is reasonable. But it's an example.) Commented Aug 10 at 10:01
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    @Hearth, have used smooth-jawed for decades on these sorts of jobs, always been fine. We're want to pull it out, not tear it out or the contacts with it. Commented Aug 10 at 10:03
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    Success, thank you! I followed your instructions exactly, though I experimented with different gripping tools. Commented Aug 22 at 13:29
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    @harlandski, oh good, glad you got a good result and you're very welcome :-) Commented Aug 22 at 20:07
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    And the happy ending is that I have now fitted a new membrane, and the keyboard is working again Commented Aug 27 at 11:41
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Use a pick or needle to pick (the needle of a compass is pretty useful here) towards the non-contact side of the connector, poke through the remnants and try to lever them out. A bit of contact spray may loosen any corroded and sticky parts.

Other than that, try and leave the contacts alone (if you're very careful, you could at best very carefully poke them to the side with a sharp piece of wood like a match or a toothpick) - they're easily bent and will no longer make proper contact with the new membrane. As the connectors are no longer made, they are relatively hard to come by and expensive.

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  • Poking each of the contact springs individually with a pin could help loosen metal corrosion, if that is what's holding the flex cable. Commented Aug 8 at 15:44
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    I'd leave the contact pins deliberately alone - they're easily damaged. Commented Aug 8 at 16:37
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A pair of needle-nose pliers might let you get a better grip of the membrane cable than tweezers allowed.

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