Graeme Hill's Dev Blog

Fixing a Cherry MX switch when the stem comes out with a key

Star date: 2014.221

I recently bought a WASD V2 Mechanical Keyboard with clear mx switches and sound dampeners. I actually only got the sound dampeners so that I could try them out and I decided that they reduced the travel too much so I needed to remove them. Luckily the keyboard came with a key puller so it seemed like an easy job. I made sure to follow the instructions given on their support video but on two of the keys the stem actually came out with the key (the stem is the colored part that sits on top of the spring). I don't think I did anything particularly stupid but I am also willing to accept that it may have been user error. The generous customer support people at WASD keyboards were kind enough to send me some replacement switches but in the mean time I wanted to try fixing them myself so that I wouldn't have to wait so long. Here's the process that worked for me:

Open the case

You cannot just ram the stem back into switch. You would probably damage it even if you were strong enough to get it in. You actually need to remove the entire switch and take it apart to get the stem back in, which almost definite means that you'll need to remove the case (although that may depend on your keyboard). With my WASD keyboard I was able to follow this process to open the case.

Removing the switch

When I say remove the switch I mean the entire black part that houses the spring and stem. If you have a plate mounted keyboard then this is likely a lot easier and you can probably just remove it with some tweezers like in this video. Generally speaking all of the tutorials that explain how to remove switches without soldering are for plate mounted keyboards. The WASD keyboard however is PCB mounted which means that the switches are soldered directly onto the circuit board and you will need to desolder the contacts to remove the switch and then resolder it again afterward. WASD also provides an an instructional video on desoldering switches. Since I wasn't quite as well equipped as the guy in the video I had no solder wick or solder pump which makes it surprisingly difficult to avoid melting the solder and then having it immediately resolidify in the same place. I used some tweezers with little hooks on the end to pull on the switch while I was melting the solder so that it just popped out as soon as it was melted.

Reparing the removed switch

The black casing of the switch is actually in two parts which you can separate by carefully pulling up the little flaps on the side. Once the parts are separated, take the bottom piece and place the spring on the little nob, and then put the stem on top of that. Then you just reattach the top of the switch casing to hold the spring and stem in place.

Reattach the switch

Again, if you have a PCB mounted keyboard you'll have to solder your switch back on. Make sure that you don't go overboard with the solder. Whenever you are soldering onto a PCB there is a potential to create a short-circuit by accidentally joining two contacts.

Technically speaking, the stem of a cherry mx switch should not come out at all and the support guy at WASD warned me that the switch may be compromised once it has been ripped out by accident. In my case, however, the repaired keys seem to be functioning just fine.

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