After posting the last article on refurbishing the ZX Spectrum I got a tip from Alex (a.k.a. ZX Wife) via Twitter on what I could try to resolve the issue with the keyboard as soon as the case was completely screwed down. Together with Ian she forms the team behind Mutant Caterpillar.
Try putting some isolating tape on either the membrane ribbons or TV modulator lid just in case it can help solve the keyboard problem.— 🌈ZX Wife🌈 (@zxwife) June 22, 2018
I was on my holiday break when I got the suggestion, but now I am back so it’s time to follow up on her suggestion and open up the troublesome ZX Spectrum again…
Still had some electrical tape laying around from which I cut a piece big enough to cover the length of the RF modulator
Applied the piece of tape to the RF modulator of the ZX Spectrum and the job is done
This time I closed the case of the ZX Spectrum by tightening all of the screws on the backplate. And… the keyboard works perfectly .
Interesting too see what a difference a little piece of electrical tape can make…