5251 Beamspring key not activating

[nihilist00]

I have recently acquired a restored 5251 Beamspring keyboard. It works well except for the O key which often does not activate. The symptom is that when I press the O key I don't hear a click and no character appears. This behavior is intermittent: after 2-3 presses each press yields a click and the O character appears. Then, after I stop typing for a minute or so it takes another few presses to get the O key working again.

Being the O key, this has a substantial effect on the keyboard's usability.

Can anyone provide any advice on how to fix this? It occurred to me that I could swap the O key switch over with a key that I use rarely or not at all (such as one of the ten keys in the left-hand block). Is there a simpler intervention I could try first? If switch-swapping is the way to go, can someone point me at a tutorial on how to go about doing so? I'm very inexperienced with keyboard DIY and I don't want to break my new beauty.

[dcopellino]

Assuming that I am by no means a beam spring key expert, the issue you described reminded me a similar problem I experienced on a key module present on my 3278. It seems related to a misalignment of the module key metal slats, as well described by Ellipse in this video clip, which with the service spirit of a user belonging to this community, I report.
Cheers

[nihilist00]

Thank you! That makes sense and is very helpful. Would I need to just remove the keycap of the O key when I remove the switch to adjust the spring, or will I need to remove all of them?

[dcopellino]

Thank you! That makes sense and is very helpful. Would I need to just remove the keycap of the O key when I remove the switch to adjust the spring, or will I need to remove all of them?

You'd need to slide off the whole 'module' key from behind, opening up the keyboard back plate, taking the 'module box' , or whatever it is, a part and start fiddling with metal slats. At the beginning it could seem hard to set it back, but after a little time it will look like very easy to fix things back. Don't be fearful and remember to press 'the beam' all the way with strength, preferably using pliers.....

[nihilist00]

Thank you for more helpful advice. I'll have a go at this in the next few days and report back.

[nihilist00]

My O key is now working. I simply had to form the flyplate spring ends to make them slightly closer together. Re-attaching the flyplate was the fun part. I found technique shown in this short video helpful; it involves using a hex key in a vice.

https://youtu.be/vc6LwIjzduI?si=1FEbdMoZhJB7pjw1

Thanks again for the guidance.