IBM model M switch – Enter key registers but does not click!!

[Azmodan]

I have recently added another IBM model M keyboard to the collection, for daily use of course. The keyboard itself is a 1992 UK Model M manufactured by Lexmark (this is my first Lexmark) as per the sticker on the steel plate and the blue IBM badge.

It came is a good condition with the exception of the ESC, Q and Enter keys not clicking on first test. The issue was fixed for the ESC and Q by simply resitting the stems of the keycaps, but no so for the Enter key.

In any case I went ahead and took everything apart and cleaned the keyboard, key-stems, keycaps, PCB etc., washed the plastics and checked that all the plastic rivets where in place, which weirdly enough I had only one missing, so for now I did not bolt mod like my other two IBM Model Ms.

That being said the Enter key is still not clicking (it registers and it works though)! I tried resitting multiple times, I tried pulling the actual spring a bit but nothing worked! Anyone has any ideas on why this might be and possible fixes? Worst case scenario, I will have to find a buckling spring switch and replace it.





Sorry about the picture quality. I took them late in the evening with only the mobile phone flash.

[E TwentyNine]

Try it with a standard single key in that position and report back.

[Azmodan]

Try it with a standard single key in that position and report back.

I have just tried it but it made no difference whatsoever! This is very weird! The key (Enter) feels linear and very light, almost like a "heavier" rubber dome. I also checked the barrel of the buckling spring for any cracks and the assembly of said key looks healthy and identical to the rest...

[E TwentyNine]

I'd also try reseating the key while the keyboard is tipped forward to make sure the spring is in the right position.

You might try swapping the spring with a less used key if you're comfortable with that.

If that didn't work, last thing I can think of is the pivot plate may be "off its mounts" and not moving correctly.   Getting a little screwdriver or similar and gently moving it might provide some help, or it might make it much much worse and inoperable.  I've had this happen with a bolt mod and I was prepared to open the board back up if pushing the plate didn't work.  So maybe that's a last resort if you can't live with a rubber dome enter key.

[fohat.digs]

Standing the keyboard upright on the front or the back (sometimes it works best one way, or the other) to get the spring to flop forward or back is the easy method.

I have successfully shifted a pivot plate laterally but that is tricky and to be used only as a last resort because screwing it up will necessitate a bolt-mod.

On the underside of the key stem is a tiny dimple that the end of the spring fits over. If it is not centered properly there, you might not be getting the proper action.

[nogoodnames444]

You just have to re position it a couple of times it happened to me when I cleaned it but it is very easy to fix just try putting the keycaps in a couple different directions