I’ve now had the problem for a third time: pressing a key would generate two keypresses instead of one. I figured out why a while ago but failed to take photos back then to share the problem and the solution with others.
The problem is, that when some dirt gets stuck at the top of the small ridge in the brown part of the switches, then a small metal pin will be de-pressed once the key gets pressed all the way down. That de-pressing will generated a second key-press event once the metal pin slides back as the switch moves up. To better illustrate it, here is how that looks like before and after cleaning.
You see that there is a bit of orange/yellow debris stuck at the top of the ridge. That is responsible for making a small metal needle loose contact if you press the switch all the way down. Cleaning it out fixes the problem.
Took me a while to find that this is the issue because it takes a lot of light and the right angle to spot that there is something stuck in the brown part of the switch. The last time i had this issue, i only found this after I had the switch de-soldered because reflowing the solder didn’t fix the issue.
How would increased debouncing help here? When I press the key all the way down, the contact of the metal pin is completely lost because of a physical problem.
I’ve been having similar issues lately, I had recently upgraded my keyboard firmware and I was initially thinking on looking into potential de-bounce issues, but its likely also a problem of debris because it mainly happens with a couple switches and its an intermittent problem; its very annoying for a couple days and it goes away for some time before coming back.
I will do some cleanup and see if it helps. This reminds me of the xkcd strip
Do you guys have any tips to reduce the amount of crap that gets under the keyboard? I have some skin flaking issues and it gets really disgusting quite fast.
Today I was having a lot of issues with my bksp key. I did not see any debris on the switch but I took a piece of pegwood from my watchmaking kit and scrubbed the key switch slot with it, as per josch recommendation. And voila, problem solved.
