A key on my AEK stopped working suddenly for no apparent reason.

[RoflCopter4]

A couple of weeks ago my AEK with Orange Alps was working just fine. In fact, it was in half decent condition. It was nice to type on and every key worked. I haven't used it in a couple of weeks now and when I plugged it in today to put it back in the rotation I noticed that the 'g' key was not working at all. I do not know why. I swear it worked just a few weeks ago and now it just doesn't register. I don't have the skill or materials to desolder and replace this key... I just don't understand. Why would it just stop working? Is my board now screwed?

[nubbinator]

Pop it open and clean it out.  Sometimes some schmutz gets inside the switch and cleaning it makes it work again. 

[RoflCopter4]

Well, after a lot of fiddling I managed to get it open. I sprayed the inside with that aerosol dusting stuff and generally it doesn't seem dirty. After a lot more fiddling I managed to get it back together... and it's still not working. Strangely enough, when I opened it up again I left it plugged into my PC and pushed the switch leaf against the backplate and the keypress registered fine. It just doesn't work when actually assembled. I have no idea what's going on.

[Daniel Beardsmore]

The part that you pushed back with your finger — I'm wondering if that's got straightened out, such that the slider can push past it without deflecting it back far enough.

If you compared that switch with another, I'm not sure that the difference between them would be enough to notice the wear, since they're possibly all worn similarly and it might be quite subtle. That leaf unclips fairly easily and you might need to bend it back into shape again.

[jacobolus]

As Daniel Beardsmore suggests, this sounds like an issue with the metal leaf attached to the switchplate. If it gets bent out of shape, then the slider moving down won’t sufficiently press it sideways into the switchplate to actuate the switch.

Something you could try is swapping the little switchplate-assembly leaves on your 'g' switch and on some uncommonly used switch, and see if that helps anything. You can pull them off by sliding a dental pick or similar pointy thing under the top side between the plastic of the switchplate assembly and the metal leaf, and pulling up carefully. If swapping the two switchplates does fix your 'g' key, you can probably also bend the worn out leaf back into a shape where it will work again. (That is, bend it so the diagonal part sticks out at a steeper angle.)

(Standard disclaimer: I take no responsibility if you break anything worse by mucking around with the switches.)

[Daniel Beardsmore]

Disclaimer? I hope we're not getting into blame culture here ;-)

[jacobolus]

Disclaimer because these are precise mechanisms, which can be broken beyond repair if you’re not careful. Little metal leaves are tricky to bend into just the right shape, and taking two switches apart and swapping parts on them might result in two broken switches instead of just one.

[RoflCopter4]

I guess I'll give it a shot later. That's kind of the impression I got. I've never used another AEK to compare this one against but if I had to guess I'd say that the keys are fairly worn in. The tactile feel of them is very significantly less than with my NIB Dell AT101 with black Alps, though as far as I know that could just be a difference between the orange and black switches. Bizarrely enough when I first put it back together I intentionally left the tactile leaf out to see what a linear Alps switch would be like and it still felt a little bit tactile. I can't really figure out why. It was very small but there was a slightly noticeable bump.

Anyway, I'll report back later. Hopefully I don't set the keyboard on fire.

[RoflCopter4]

Well, I tried. I replaced one leaf with another and still nothing. It works when I push against the leaf with a screwdriver or my finger or whatever, but just does not work as a switch. I really don't know why.

[rowdy]

Replacement switch time?

[CPTBadAss]

Try using a multimeter to see if the switch has a cold joint. You might have to touch up a solder joint. If not, maybe go with Rowdy's route and replace the switch.

[RoflCopter4]

Like I mentioned above, I do not have the skills nor the means to desolder or solder anything. I have a cheap multimeter but it barely works. I don't understand why the switch works when physically pushed but the slider doesn't actually operate it.

[Daniel Beardsmore]

It's possible that the plastic prong that the metal leaf presses against, is damaged. Albeit without knowing how much pressure you're applying with your finger, it seems safe to assume that this problem is subtle.

The slight linear feel with the tactile leaf removed is likely to come from the interaction between the slider and the actuator leaf. I found the same thing when I tried making linear Alps from blue Alps switches.

(The metal leaf presses on a plastic prong that presses a sheet of metal foil against a metal plate. It's called "complicated Alps" for a reason :-)

[jacobolus]

The problem is definitely not a cold solder joint. But in any event, I think the only easy way you can fix it is by desoldering the switch and swapping it with another one.

(It’s too hard to try to manipulate parts on the switchplate while that’s still soldered in. If you got the switch loose and could take it apart you could maybe figure out better what the issue is.)

[RoflCopter4]

Well, if that's the case then it's basically broken beyond any repair I could hope to manage at any point in the foreseeable future. Very irritating. I liked that keyboard.

[jacobolus]

Other possibilities include finding someone nearby with a soldering iron you could use (e.g. a hacker space), hiring someone to fix it for you, or selling or trading the keyboard to someone who can fix it or wants to harvest parts for other projects.

[RoflCopter4]

Good news! I finally decided to just say screw it and try violently bending the leaf mechanism to see if that would make the key work... and it did! I bent it way beyond what the other keys are bent and now it seems to be working just fine. Strangely enough, even though I didn't bother to put the tactile leaf back in I can feel a small amount of tactility. I don't know if every key does that or if I've made it do that by bending the switch leaf so much.

[Daniel Beardsmore]

The actuator leaf does add a noticeable amount of tactility; see under 緑軸 ("green axis") here:

http://www5f.biglobe.ne.jp/~silencium/keyboard/html/alpssw.html

I mentioned a few posts up that I experienced this with blue Alps with the click leaf removed.

[RoflCopter4]

Yeah, I saw you mentioned that. I was just surprised at the degree of it, especially considering I've heard multiple times about how "smooth" Green Alps are. This is a good thing because I can't seem to get it to work with the tactile leaf in the key at all, so I have to leave it out. Better some tactility than none.