NO BUG: "Sticky" (mechanical) keys

Discussion around the SwissMicros DM42 calculator
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mcc
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Joined: Fri Jun 23, 2017 5:10 am

NO BUG: "Sticky" (mechanical) keys

Post by mcc »

Hi,

I noticed, that "suddenly" (read: it was not that way before) the "2","3" and "R/S" got kinda "sticky" feeling when pressed (damn is this difficult
to explain...lets try)
The key itsself (what is touched with my thumb) is NOT sticky. But when the key is pressed down it sounds/feels that the key needs to be
torn away from something with some "higher" force. This only happens, when the key has rest for a while and after this "initial" press of the key the "stickyness" goes away until the key has again rested for some time.
It may be, that something gets into the mechanic of the keys somehow (dont ask me about the "how"-part of "somehow.... :) )

I had opened the calculator, carefully removed the pcb and cleaned the surface of the backside of the keys and the folio (covering the metal
domes) with a cotton stick (word? Q-Tips I mean). But it does not help that much.
It seems, that the tiny tip on the back of the keys, which directly presses onto the dome isn't able to move easily over the surface of the folio anymore.
Any safe ideas how to clean the keys/the affected surface of the folio more intensily without risk any damage to this wonderful gem of math?

Thanks a lot for any help in advance!

Cheers
Meino
DM 42 - SN: 00373, Firmware release v.:3.22. / DMCP 3.24. as compiled by SwissMicros
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ijabbott
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Re: NO BUG: "Sticky" (mechanical) keys

Post by ijabbott »

Isopropanol (Isopropyl Alcohol / IPA) is generally good for cleaning electronic equipment. Use the 99% pure kind, not the 70% kind.
mcc
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Re: NO BUG: "Sticky" (mechanical) keys

Post by mcc »

Hi,
thanks for the hint ! :)

Is there any glue to hold parts of the keyboard in place or a printing
which get accidentally solved since IPA is a good solvent ?

Cheers!
Meino
DM 42 - SN: 00373, Firmware release v.:3.22. / DMCP 3.24. as compiled by SwissMicros
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ijabbott
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Re: NO BUG: "Sticky" (mechanical) keys

Post by ijabbott »

mcc wrote:
Sun Feb 25, 2018 6:06 am
Is there any glue to hold parts of the keyboard in place or a printing
which get accidentally solved since IPA is a good solvent ?
I can't think of any parts of the calculator that IPA would dissolve. As a test, I just liberally sprayed the front and back of the keyboard and the sticky-backed plastic film covering the key domes with IPA from a spray bottle with no ill effects. Admittedly, I tested it on a piece of 3M Scotch Magic Tape first. It doesn't even dissolve the glue on the sticky side on the tape, which might be bad news for you, depending on the cause of your sticky key issue!
mcc
Posts: 277
Joined: Fri Jun 23, 2017 5:10 am

Re: NO BUG: "Sticky" (mechanical) keys

Post by mcc »

Hi,

OH GREAT! Thanks for experimenting!
I will give it a try (I have 1 Liter of IPA to clean the printing bed of my 3D printer...so no problem at all
get "some IPA" ... :) )

Cheers!
Meino
DM 42 - SN: 00373, Firmware release v.:3.22. / DMCP 3.24. as compiled by SwissMicros
toml_12953
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Re: NO BUG: "Sticky" (mechanical) keys

Post by toml_12953 »

ijabbott wrote:
Sun Feb 25, 2018 1:15 am
Isopropanol (Isopropyl Alcohol / IPA) is generally good for cleaning electronic equipment. Use the 99% pure kind, not the 70% kind.
When I think of IPA I think India Pale Ale!
Tom L

Some people call me inept but I'm as ept as anybody!
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ijabbott
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Re: NO BUG: "Sticky" (mechanical) keys

Post by ijabbott »

toml_12953 wrote:
Sun Feb 25, 2018 4:14 pm
When I think of IPA I think India Pale Ale!
I wouldn't recommend spraying beer on the calculator internals! :)
grsbanks
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Re: NO BUG: "Sticky" (mechanical) keys

Post by grsbanks »

...or drinking the other IPA!!!
There are only 10 kinds of people in the world: those who understand binary and those who do not.
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ijabbott
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Re: NO BUG: "Sticky" (mechanical) keys

Post by ijabbott »

grsbanks wrote:
Sun Feb 25, 2018 7:05 pm
...or drinking the other IPA!!!
It used to be one of the ingredients of Henderson's Relish, but they changed the recipe to remove it.
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