re-inserting a blue stem into a locked key.

[dfj]

The problem : we have accidentally pulled the stem out of our plate mounted switch, typically by pulling at an angle to the right hand side while attempting to remove a key-cap. I'm showing how to reassemble with a worn out switch I had handy, even though it's not plate mounted at present. Hope it is clear enough that the technique will work for your plate mounted problem, should it arise.
  If your switches are pcb-mounted, there is no problem, just open the switch and reassemble, using a fork-of-doom or summat.
g'luck.

[ Attachment Invalid Or Does Not Exist ] 26902[/ATTACH] [ Attachment Invalid Or Does Not Exist ] 26901[/ATTACH]
spring first, then stem,
[ Attachment Invalid Or Does Not Exist ] 26903[/ATTACH] [ Attachment Invalid Or Does Not Exist ] 26904[/ATTACH]
force back in, angling the right hand side catch first, then forcing the left side catch through... takes a bit of force, but not crazy much.
[ Attachment Invalid Or Does Not Exist ] 26898[/ATTACH]
now, the key will only depress part way - this is because the clips at the bottom of the stem have not engaged with the white follower/clicker yet.
[ Attachment Invalid Or Does Not Exist ] 26899[/ATTACH]
push straight down, hard - feel free to use your thumb.
[ Attachment Invalid Or Does Not Exist ] 26900[/ATTACH]
it hurts, but it will click in, then the key will work again.

like, don't rip your stems out, kay?

dfj

[nolliepoper]

Thanks.

[nolliepoper]

The whole reason my stem came out was because the red ring key puller popped off one side, thus leading to the force only acting on one side of the key cap.
Lesson learned, don't use those red ring key pullers unless your keys come off easy.
I luckily have two strong paper clips to work perfectly and haven't had any problems.
[ Attachment Invalid Or Does Not Exist ] 26905[/ATTACH]

[redpill]

Could this technique be used in reverse to swap stems in plate mounted boards without desoldering?

[dfj]

I'm with rip on this - it's risky as hell.

If you have torn a key out of a plate mount by accident, (I'll edit the post to make that clear), then you can likely get it back in - but if you do it 100 times, I'd guess that some will be b0rk'd.

[dfj]

PS: cherry switches desolder and resolder very cleanly - I was surprised with how much less work it ended up being than I expected. I've desoldered three boards worth, one of which was the irritating new 'leadless' crap, which wants either higher temps, or for you to add normal solder to each joint first, to lower the fusion point - still, just takes more time, not too fiddly, not much to go wrong.
  I suggest practicing a bit desoldering and resoldering resistors and whatnot on some scrap pcb whith through-hole components, then tear up yer board for the lulz, yup.

g'lucks,
dfj