Cherry keyboard maintenance for dummies

[j'ordos]

Hello all, I just purchased a used cherry mx8100 off of e-bay, concluding my search for an affordable full n-key keyboard!
I'm quite happy with it, but there still are two faults noticeable: the V key was a little dislodged when it arrived, and didn't always register. I've forced it back in position somewhat and it's better, but still not optimal.
Second: the Ctrl key has a similar problem, though it doesn't appear to be dislodged. I guess the keyboard saw some heay copy/paste action during it's lifetime?

Anyway my question is what I could do about this, if anything at all? I have no experience in keyboard maintenance whatsoever.
Sorry if a similar thread already exists here or if I'm posting this in the wrong forum!
Thanks!

PS the model number is G80-8113HRBUS-2 should it be helpful

[keyb_gr]

On the V, try removing the keycap (pull straight up, if it won't come off by hand then fabricate some keycap pulling tool that will do same) and wiggling the switch. It shouldn't move a bit, otherwise it may need resoldering. Try activating it with the keycap off, is it still intermittent then?

It shouldn't be too hard to access the back of the PCB for contact resistance checks with an ohmmeter (multimeter) - check the MX switch datasheet for the pinout - or resoldering if necessary. These Cherry boards are usually clipped either on the top or all around, that's pretty much it.

[j'ordos]

Thanks for the reply, I removed the keycaps; both keys seemed to be working fine when I pressed them at that point. I reattached the keycaps and the v still works fine but the ctrl key again became unresponsive. Can it be a problem with the keycap?

[timw4mail]

Thanks for the reply, I removed the keycaps; both keys seemed to be working fine when I pressed them at that point. I reattached the keycaps and the v still works fine but the ctrl key again became unresponsive. Can it be a problem with the keycap?

Make sure the keycap is reseated all the way. Sometimes, depending on how the keys are made, the key will snap into place.

[j'ordos]

It appears to be inserted correctly

[timw4mail]

It appears to be inserted correctly

Is the stem intact?

The only thing I can think of is that the stem on the keycap is broken, so you aren't pressing straight down onto the keyswitch.

[j'ordos]

I can see nothing wrong with the keycap, the stem looks intact and there's no crud. But I have noticed it's a matter of pressing the key firmly and in the center. Even with the keycap removed I have to make sure the white thingy (sorry don't know the terminology edit: ah, actuator seems to be the right expression! ) is pressed way down or I get the same 'sometimes-okay-sometimes-not response. Is this normal when typing without keycaps or is there something wrong with the switch?

[timw4mail]

I can see nothing wrong with the keycap, the stem looks intact and there's no crud. But I have noticed it's a matter of pressing the key firmly and in the center. Even with the keycap removed I have to make sure the white thingy (sorry don't know the terminology ) is pressed way down or I get the same 'sometimes-okay-sometimes-not response. Is this normal when typing without keycaps or is there something wrong with the switch?

Sounds like a dying switch.

[j'ordos]

It couldn't also be an electrical fault in the board? I haven't tested it with a multimeter yet, as suggested by keyb_gr.
Otherwise, would it be hard to try and replace those? (I could use a switch from one of the unused programmable keys for example)
edit: the board has cherry mx black switches

[keyb_gr]

edit: the board has cherry mx black switches

Err, didn't you write "white thingy" for what should be the stem?

Do try measuring contact resistance. The switch should become a pretty good short (<1 ohm, the spec says 200 mOhm but that's hard to measure) about halfway down. If it doesn't, one might want to open up the switch and look what's going on or just swap it with another one right away. Good unsoldering technique recommended to avoid damaging traces.

[j'ordos]

Whoops my mistake, I was looking at the colour of the 'casing' thinking that was the part that determined the type; they are white ones then
I'll take a look at it, thanks!
edit: lacking access to a multimeter I went ahead and opened the switch. As far as I could tellI think it's that strip of metal that's a bit worn out, not staying firmly in place anymore. I tried reinforcing it with some paper which improved performance for a minute, but now it seems like it's actually working worse than before Before actually trying my hand (or rather, someone else with more proficiency) at de/soldering I'll try to get hold of a multimeter though.
Thanks you all for your help!

PS since I'll probably get more damaged switches given the board's overall state (it looks like it had a pretty hard life) where could I best try to get hold of replacement switches given my location of Europe, Belgium? Cherry itself sounds like a safe bet, it's based in Germany no?

[j'ordos]

Hi again,

It's been a while but I finally got the keyboard to a repair shop and the ctrl is working fine now, at the expense of one programmable key which now uses the faulty switch instead.
Anyway I also have a problem with the software that goes with it, for programming the extra keys. I downloaded the latest version from the Cherry website (software tools 5.5), but the designer program complains about old firmware in my cherry G80-8113HRBUS-2. When I try to update it an error message pops up telling me something about incompatible modules. I can still continue but don't want to destroy it, so I decided to ask around here, anyone had this problem before using these boards? Do I need an older version of the software? I can't ignore the problem because the program won't let me update the configuration without upgrading the firmware first.

Thanks in advance!

[sixty]

Hi again,

It's been a while but I finally got the keyboard to a repair shop and the ctrl is working fine now, at the expense of one programmable key which now uses the faulty switch instead.
Anyway I also have a problem with the software that goes with it, for programming the extra keys. I downloaded the latest version from the Cherry website (software tools 5.5), but the designer program complains about old firmware in my cherry G80-8113HRBUS-2. When I try to update it an error message pops up telling me something about incompatible modules. I can still continue but don't want to destroy it, so I decided to ask around here, anyone had this problem before using these boards? Do I need an older version of the software? I can't ignore the problem because the program won't let me update the configuration without upgrading the firmware first.

Thanks in advance!

I got the same error when first flashing my G80-8xxx (forgot the exact number, board is now i procession of lowpoly). In my case I ignored the warning and was able to flash the new firmware to it fine. The first thing the software does is backup the keyboard firmware, so even if you bust it you should still be able to replace it later if it ends up not working.

[Rajagra]

First the obvious: don't connect the keyboard via a PS/2-USB convertor or KVM switch while doing the update.

When I did mine I think I had that error. It seemed to me it was choosing the wrong firmware name to match the keyboard model. So I tried telling it to use firmware with a closer name match, but it failed to proceed. Eventually I let it choose the file itself, and it went ahead.

NB I ignored common sense and tried the upgrade through a KVM switch (I only paid a pound or two for it so I lived dangerously.) Halfway through my KVM beeped and the keyboard became unresponsive. I though it would be ruined, but when I powered off the machine, plugged the board directly into the PS/2 port and powered up, it allowed me to do the upgrade successfully.

So it is quite resilient in that sense.

[j'ordos]

Great, thanks a lot guys!! Somewhat relieved that the board probably wouldn't become inoperable I went ahead and upgraded the firmware succesfully and I have encountered no problems so far.
The board is in the PS/2 slot (doesn't have a usb connector) and I don't know what a KVM switch is so I'll assume I'm not using it
Thanks again sixty&rajagra

[j'ordos]

Unfortunate double post

[lowpoly]

forgot the exact number, board is now i procession of lowpoly

It's a G80-8927LSCGB.

[j'ordos]

Got yet Another question: what is the size (in pixels) of the piece of paper you're supposedly able to put over those relegendable keys?

[timw4mail]

Got yet Another question: what is the size (in pixels) of the piece of paper you're supposedly able to put over those relegendable keys?

Pixels are not a measurement that is directly translatable to paper.