IBM Model M : reseating keys properly

[Special K]

I took apart my model M for a cleaning last night and when I was reassembling it I noticed that some of the keycaps I replaced did not seem to be seating properly.  Whereas a normal model M key has a definite tactile point and audible click/ping noise when the spring buckles, some of my keys just kind of sunk down with no definite tactile point or click/ping noise. 

I tried taking the caps off and reseating them, but the issue remains.  I have not yet plugged in the keyboard to see if these keys are actually registered when pressed, but I don't see any point in using the keyboard if the tactile and audible feedback is gone.  The keyboard worked, felt, and sounded fine before I disassembled it.  The springs under the keys that don't seem to be seated properly don't look any different than the springs under the keys that are seated properly.

Do I have broken springs/switches, or is there some trick to reseating the keycaps properly?  The enter key on the numpad in particular is giving me the most trouble.  Even though the key appears to be seated and the stabilizer bar appears to be latched to the plastic backplate, the key itself doesn't have any tactility; pressing it just feels like pressing into mush.

[E TwentyNine]

The trick is to tilt the keyboard forward, away from you, when seating the keys.  You'll see the spring tilt forward in the barrel when you do this.

[Snowdog993]

One thing to check is to be sure that the spring is guided properly in the stem itself.  Make sure the key stem isn't upside down too!  Um, you didn't pull on any of the springs or take any of them off, I presume.
If a spring is doubled over from not paying attention when you put the stem in, be very careful and unbind it from the barrel without taking it off.  You might need a paper clip to do this.  (I can't explain it better than that.)
Make sure that all the springs are sticking straight out of the barrels too.
Hope this helps, I don't know if it will or not. 

[fohat.digs]

If you look into the key stem, there is a little "ski slope" affair leading to a dimple where the top of the spring seats.

If the spring is not properly centered on that dimple, for whatever reason, the spring will not buckle properly.
 

[Touch_It]

Everyone else has already stated the troubleshooting steps.  Only thing I might add is that sometimes it can take multiple tries to re-seat keys properly.  I've never had issues on a Model M but have on my Model F, though the principal is exactly the same.

[Special K]

The trick is to tilt the keyboard forward, away from you, when seating the keys.  You'll see the spring tilt forward in the barrel when you do this.

Thanks, this proved to be the key.  I held the keyboard vertical top/logo side facing downward while installing the keycaps and everything lined up fine.

The other problem I had was with the + and Enter keys on the numpad.  Apparently it matters which way you attach the stabilizer bar.  One end of the stabilizer bar is slightly longer than the other one.  That side needs to attach to the bottom end of the key, otherwise the key will not press down properly.

The Model M is by far the most finicky keyboard I have used (so far).

[Melvang]

The trick is to tilt the keyboard forward, away from you, when seating the keys.  You'll see the spring tilt forward in the barrel when you do this.

Thanks, this proved to be the key.  I held the keyboard vertical top/logo side facing downward while installing the keycaps and everything lined up fine.

The other problem I had was with the + and Enter keys on the numpad.  Apparently it matters which way you attach the stabilizer bar.  One end of the stabilizer bar is slightly longer than the other one.  That side needs to attach to the bottom end of the key, otherwise the key will not press down properly.

The Model M is by far the most finicky keyboard I have used (so far).

If you think M's are finicky, don't ever take apart an F.