My AEKII keys started to fail. Is it fixable?

[DMA]

Hi,

I've recently bought 4 AEKIIs (M0312). Currently using 2 - one at work, one at home. (Other 2 will be converted to NKRO ones a bit later - plate is corroded in a couple of places, the switches there don't work, so overhaul is in order and I have 1000 1N4148s laying around - why not make proper matrix for it..)

Anyway. After 2 weeks of usage several keys (mostly F-keys) started to fail to register.
Is it a known problem? Granted, the keyboard is 27 years old - but my 30 year old IBM one still works perfectly after all.
Wiki doesn't have much about that (or I need better reading glasses).
Any advise on what to do about it?
I can probably cannibalize one of the keyboards for switches - but I don't want to, I'd rather gift it to my mac-using friends (no point selling it, it will probably cost me like $50-$100 to rebuild it not accounting for time spent, and the ebay price is $30ish ).

[Muirium]

Heh, most Mac users don't have a socket to plug those ADB cables into, either! The AEK layout is still excellent for OS X though, you just need to bridge the gap with USB yourself.

Anywho: your question. I'd blame it on the switches. Alps don't age well. Strange it would be the function keys, though. They typically get very little use indeed on Macs.

[DMA]

Well, those gifted keyboards will be converted to USB - with one of these https://www.instagram.com/p/BFlO57AAriw ... Xmch1eK00/ or completely rewired, doesn't really matter. I suspect that the deciding factor will be "how many extra kitprogs I'll have laying around"

"Alps don't age well" is sad news tho. What usually happens to them? Membrane fails?
*tries not to think about convering alps to capsense*

[Muirium]

Membrane? No, they're discrete switch modules. They can be desoldered and replaced individually. What actually goes wrong in them is the two metal leaves inside the switch get worn with use and and eventually lose their feel and ultimately their actuation entirely. The guys who're into tearing down switches can fill in the details. Much too small and fiddly for me!

[DMA]

Those switches have a membrane inside. Thin leaf of copper, it seems.

Anyway, need to finish reviving the 122-key model F dreadnought I have, then will figure out what to do with those.
I think that "don't age well" part is because membrane corrodes or just cracks from repeated stress. I hope they can be recovered, but if not.. I've bought 4 of them for $50 after all

[Muirium]

There's either no membrane, or they're not the classic Alps <insert random four letter initial I can't possibly remember here> switch. I've long given up trying to understand the dreaded Alps Vortex, or indeed lengthy initials in general! But what I can tell you is that AEK IIs always contain either Alps switches or Mitsumis and none of those have any kind of membrane whatsoever.

Membranes are a way around discrete switches. The idea is to have three large membrane sheets, two acting as contacts and circuit paths, with the middle as an insulator until squeezed. When a key presses the membrane, the middle layer can't hold the outer two apart and a circuit is created between the corresponding contacts.

Mechanical key switches don't need a membrane. They simply contain two metal contacts, one of which moves with the slider, and they touch when the switch reaches the actuation point.

If your Apple keyboards contain membranes, they sound more like AppleDesign junkers than AEK IIs.

[DMA]

See that square thing in the middle of this diagram? Copper one in center of this? That's membrane.
It's not as large - but those things started creeping into the keyboards quite a long time ago..

[Muirium]

How can copper be a membrane? Are you sure you don't mean "contact"?

I'll admit that I'm not into switch micrography, and there's plenty of people here who know more about the innards of Alps etc. than I do. There are certainly some oddballs in the family. But that term just does not compute. Far as I know, the metal components have names like leaves. Membrane has a specific meaning in keyboards, like its place at the heart of the Model M.

Whatever the name, why do you think that part is at fault: have you opened up some switches and spotted something awry? From what I've heard, and felt, Alps go bad in the leaves/switchplate/contacts/metal bits. They suffer from basic wear more than their MX counterparts, especially once dirt gets inside.

[DMA]

I opened one that didn't work - lots of green powder in there. That's copper oxide. Haven't explored further - need to solder out the switch, don't have soldering iron at work.

Thought it's a known problem and people know how to fix it quickly.
But thanks for alps integrated dome idea - even thoroughly corroded switches can be restored by converting them to something like this, I think.

[Muirium]

Alps Integrated Dome spoiler: I have some, and they're not great. Okay, but not as nice as Complicated Alps. Plus that kind of conversion sounds a lot of bother. Uncharted, too.

Maybe a project for *after* you've answered all our capsense controller prayers!

[DMA]

Definitely *after*.
Unless enough keys stop working to leave me without my daily driver - not going to $5 logitech again!