After a painfult desoldering process with a lot of pin un-bending i have disassembled my chicony 5181 with futaba MAs.
The board was pretty nasty with a lot of dirt in it, and half the switches click weak or not at all. So i've decided on a full stripdown, and then replacing the switches with ones from a donor board that didn't power on, but had pretty much brand new switches.
- DSC_0594.JPG (3.33 MiB) Viewed 4384 times
After i had all the switches free from the board though, i started thinking why is it that some have stopped clicking. The switch mechanism itself is rather interesting to me and i really like those, so i thought why not to open some up, as there is nothing to loose now since they're in such a bad condition.
- DSC_0598.JPG (1.81 MiB) Viewed 4384 times
First, cut four melted plastic tops of the pegs that hold the housing together like this.
- DSC_0600.JPG (1.98 MiB) Viewed 4384 times
Then, find a place where the housing comes together from two parts. gently stick a knife in there and pry both sides a little. After that you should be able to just slowly pull the bottom of the housing out. Do not press the slider, or the switch will literally EXPLODE onto you.
- DSC_0606.JPG (3.13 MiB) Viewed 4384 times
After examining clicking and not-so-clicking switches, i noticed the plate spring on those is bent in a bit different way. On the switches that have stopped clicking, the outermost "arms" of the spring, are slightly bent towards the bottom of the switch, in such a way that if you lay the plate spring on a flat surface, it's not looking flat.
- DSC_0607.JPG (2.04 MiB) Viewed 4384 times
It might be hard to see but if you look closely at the outer part of the spring, you can see it is not in line with the rest of the spring. Those visible "kinks" or "bends" on the outer arms, i think are there to provide sort of a buckling point around which the entire spring inverts. I did a mistake of straightening those first, and while it STILL MADE THE SWITCH CLICK AGAIN, it altered the feel a little bit - i would not reccomend doing that. what you want to try to do, is just gently bend the arms back, so that the spring looks close to absolutely flat - it has to be able to stay in a stable state when flipped in BOTH directions, from what i understood while playing with the switch. So the spring should not be pre-bent too much in any direction. What i think happens over time is the spring fatigues with use, and gets slightly bent towards the switch bottom. this moves the flipping or, buckling "point" more towards the bottom of the switch, until the spring CANNOT flip before you already bottom out the switch, hence there is NO click at all. I have tried that on few switches, and all of them eventually started clicking, It is not a precise method in any way, because the bending has to be done very delicately and just a slight amount, maybe there could be a tool made in which you could just place the plate spring and press on it to bend it back just the right amount everytime. Doing it with fingers or pliers though, it's possible to bring the click back! I might try to do a small video soon explaining it more visually. I hope somebody finds this interesting. Cheers!
