Quite unhappy with my Cherry G80-3000-LQCDE2/01

[lelaurent]

Quite unhappy with my Cherry G80-3000-LQCDE2/01

I recently bought a Cherry G80 to end my keyboard troubles (consisting of a miserable '03 Apple Keyboard with hardly depressable caps if not hit at the dead center), but alas, this board made my real troubles just begin.

The day I got it, I removed a keycap to see what switches were underneath. Has never been a problem with any keyboard I owned, but here, deadly error. I did not remove the cap straight up, but up-and-to the side and managed to pop open the switch underneath. It hasn't worked since, even not after putting the parts back together in all possible ways.

Next problem with this board, it can't get all the key combinations I use. E.g. Ctrl-Alt-Up totally locks up the board until I press Ctrl-Alt again. I need this shortcut for my Linux desktop!
Never had a board which can't get all common shortcuts.

Final problem: It comes with a USB plug and a PS/2 adapter. I am torn apart between laughing and crying: In the BIOS, the Board works with both PS/2 and USB. In GRUB, only the PS/2 connection works, so if I want to select Windows to boot into, I have to plug it in via PS/2. Which I promptly have to undo once Windows has booted, because there'll be no way in hell to get a single registered keypress out of this beast in Windows while connected via PS/2! :DDD
Linux works with both connections.


Maybe someone has some pointers for me, or is willing to buy a G80 with a busted Pause key

[Muirium]

Odd that a switch would be the weak point on that board. MX switches are reasonably tough and will usually survive quite a bit of rough handling, let alone key pulling. But they are weak when opened: their shells are formed from two separate bits of plastic which clip together. I've not encountered an improperly closed one in the field, myself, but it can happen. Typically, the only time they're ever opened is on purpose when people are doing mods, like switching springs.

Your other issue is rollover. Does the 3000 say anywhere on its box that it has NKRO / N-key Rollover when on PS/2? Even so, mods and arrows shouldn't be a problem on 6KRO USB.

http://en.wikipedia.org/wiki/Rollover_(key)

[lelaurent]

Your other issue is rollover. Does the 3000 say anywhere on its box that it has NKRO / N-key Rollover when on PS/2? Even so, mods and arrows shouldn't be a problem on 6KRO USB.

It doesn't have NKRO, but this is still strange, yeah.

[Muirium]

Sounds fishy. I'd try it on a couple of different machines to see if the behaviour is always the same.

[Broadmonkey]

I am quite impressed that you were able to tear the switch apart, you must really have tried to wriggle it to the sides instead of lifting it. I think you might have put the switch top on the wrong way, since the switch no longer works. When you put it on the wrong way you bend the contact leafs inside the switch and and so it will never reach the other leaf when the stem is pressed down.
Try opening the switch again and bend the leaf back so that is always touches the other leaf when no stem is inserted, test it by putting in the stem back on the spring inside the switch and press down, if they touch it should be working again.

[Halvar]

For the broken keyswitch, maybe the photos in our wiki can help you make it work again:
http://deskthority.net/wiki/Cherry_MX

For PS/2, the only reasons for it not working in Windows I can imagine are that it was either plugged in after the boot or in the wrong plug. PS/2 is not hot-swappable, if you plug it in after the computer started, Windows won't recognize it. And on most older mainbords there are two PS/2 plugs, one for the keyboard and one for the mouse. I'm pretty sure you know all that, but anyway.

GRUB: I don't know a lot about GRUB, but it's a very simple program running before any OS was started, so I would assume it uses BIOS functions to read the keyboard, so that's quite strange. One thing I'm pretty sure of is that GRUB won't detect hot-plugging a USB keyboard, but if you start the computer with the keyboard plugged it, and it works in BIOS, I'd assume that it also worked in GRUB. Some BIOSes have a setting "Support Legacy USB" or something like that, maybe this can help.

[lelaurent]

I am quite impressed that you were able to tear the switch apart, you must really have tried to wriggle it to the sides instead of lifting it. I think you might have put the switch top on the wrong way, since the switch no longer works. When you put it on the wrong way you bend the contact leafs inside the switch and and so it will never reach the other leaf when the stem is pressed down.
Try opening the switch again and bend the leaf back so that is always touches the other leaf when no stem is inserted, test it by putting in the stem back on the spring inside the switch and press down, if they touch it should be working again.

Yeah I used a pen to pry it open. Don't have the appropiate tool, but try to be more careful in the future...
Yeah I initially put it in the wrong way, you're correct. It stopped working because of that. I tried bending back the leaf in the middle of the switch, hasn't worked yet. But thanks for the tip!
I'll try it some more and then try ordering a new switch and soldering it on. If I destroy the keyboard in the process, at least I won't have anymore problems with it

PS. Halvar thanks for the photo links, should be helpful....
PPS. I'll test it on another computer later.

[Daniel Beardsmore]

Most Cherry G80 series keyboards are PCB mount, so you do have to be more careful with removing keycaps as you're tugging directly on the solder joints, which are all that hold the switch in place. The G80-3850 ("MX BOARD 3.0") and other products such as those from Filco and Leopold) are plate mount: the switches are also secured into a steel plate (though if you're unlucky you can actually rip the switch apart). The steel plate also stops the switch top from coming off, much to the annoyance of modders (but some people have actually ripped the slider out through the top of the switch).

I always take extra care when pulling keycaps from my G80-3000LCQDE-2/01 to avoid damage.

I never encountered any problems with my G80-3000 with hangs induced by bugs in the blocking implementation in the controller. I doubt that I ever tried ctrl+alt+up (not used in any software I encounter) but I can try that when I'm back at work tomorrow.

[Laser]

Yes, the top part of the switch comes apart real quickly with those keyboards (i have an ANSI one equivalent with MX clears). In the worst case, unsolder a rarely used switch and solder it in place of the non-working one (swap the two switches), but indeed if you manage to bend the leaf correctly it should work (assuming it is still correctly soldered on the PCB). If you have some curved pliers, you can use those as a fork to remove keycaps from the side, instead of a keycap puller - basically you insert the pliers under the keycap, try to get them close to one another near the keycap "+" support, then pull the keycap; if done correctly, the pliers will pull the key, while at the same time keeping the top switch part pushed in its place.

[lelaurent]

Laser: I'll probably need to get those pliers since I'm going to keep the keyboard - I think I've discovered what caused the non working key combo!
The switch was stuck in always-on position. Invisible in operating system. No LED activity. Only visible by using showkeys from the commandline.
The keyboard now correctly reports Ctrl-Alt-Up.

I tested this on my laptop and will try this on my main PC tomorrow! I think this surely also caused the problems with the USB/PS2 connection. Yeah!
Thanks for all the knowledgeable replies.

[Laser]

Glad that you solved it in a satisfactory manner