OK done with responses for a bit
Now... back to my M2. As it's very very clean for it's age, I decided to tear into it and repair it.
Now... a word of caution:
Buckling Spring keyboards are not for the faint of heart to repair or take apart. If you take one apart, be forewarned that there are (what seem like) MILLIONS OF PARTS that can fall out or go wrong.
With that said, lets go on.
Faceplate, like the rest of the keyboard is really clean. Not too different looking than a normal membrane keyboard upon first inspection.
BUT... wait. This is a picture that has the parts out
Hmm.... and the crescendo builds to this:
Starting to get the picture? All of those little guys, make the contacts close.
If you don't put them in the right spot, and have them perfectly aligned, you will find keys that don't work at all.
The picture above is the real electrical part. Rubber isolator over a common dual layered plastic contact pad. In the upper right are the indicator lights, and the signal multiplexer that will feed the data to the computer in usable terms.
What is a buckling spring?
Here is one of 103 keys (or so):
When you press on the key itself, you are pressing down on a surrounded housing that pushes the spring in the cylinder down. The spring is weak enough to offer side pressure resistance, and instead of going directly down, bends into a "C" shape while compressing. When the spring cannot bend sideways anymore, it is forced to compress and it pushes the contact paw firmly into the rubber isolator, which absorbs damaging shock that would otherwise eventually kill the plastic membrane underneath, and strikes the contact. This happens with a "CLICK" or "CLACK" (depending on how you hear a loud keyboard like this).
Membranes keyboards are the most readily available keyboards that you can get, and if you weren't around in the early years of computing or you just never had the chance to use an old buckling spring keyboard, then I don't count that against anybody. The main reason why, is that membrane boards are cheaper to make, easier to make, and are quieter.
They function in the same way as buckling springs nearly, but instead of springs, the keys are literally on top of what looks like the rubber part of a toilet plunger, and as you hit the key, the plunger folds and hits the contact pad. Not only are the plungers circular, but they can be made extremely cheap, and in mass quantities.
But, getting back.... lol.
The reason my M2 was making my computer lock up was one of the buckling springs became misaligned and was making direct contact with the pad. The computer does NOT like this when it boots up. So, I had to tear it apart.
I also found my left shift key return assist is partially broken, so I gotta fix that.
Now you know.