Focus FK-2001 Left Control Key Issue

[thefarside]

I have three FK-2001 keyboards and two of them intermittently do not register a key press on only the left Control key. One has Alps clones and the other has genuine Alps.

My third FK-2001 is a new old stock which I think is why it’s issue free.

I think the issue is me pressing the key too hard and possibly off-center key presses. Has anyone ever experienced an issue like this? I took apart the genuine Alps switch and everything looks good. Pressing lightly on the contact leaf reliably registers key presses and the slider looks fine. I attached a picture of the switch in case there’s something I missed.

Any help would be appreciated. I might try to be lighter on the key but I’d prefer it to take my abuse

[poyovimenakafudraga]

You can clip off the pusher leaf from the top and then split the plate (carefully, it's still riveted on the bottom). Then you can try blowing the dust out, or soaking it with alcohol and then blowing out, you get the idea. The problem is caused either by dust or by oxidation, the latter being harder to fix. If this doesn't fix it, you'll have to transplant a contact plate from a working switch.
EDIT: just crossed my mind, it might be a shoddy solder joint, it's a pretty common fault on Focus, Chicony, Ortek and similar boards. Check that out before fiddling with the contact plate.

[thefarside]

Thanks I’ll check out the solder joints first. The case is easy to open - no screws!

[Polecat]

Thanks I’ll check out the solder joints first. The case is easy to open - no screws!

Also check for cracked traces on the PC board going to that switch. The switches at the corners are especially vulnerable as they hit the deck first if the keyboard gets dropped.

[thefarside]

Thanks again for the advice! I followed both tips and first checked out the PCB. There were no obvious cracks on any of the traces. I included a picture of the left control key PCB area and the whole board.

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I then removed the contact leaf and blew some compressed air but that didn’t seem to make improve the key. This was my first time opening up the switch plate assembly and I wasn’t sure if I could remove the switch plate, so I decided to open up the assembly a little more and blow air at different angles. I’m not sure if this is the best method but I used a toothpick to open up the assembly.

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I also swapped the contact leaf from the blank key next to it. That seemed to fix it! It’s 99% reliable now based on my limited testing, and can go back to being one of my daily drivers.

I also learned about a nice way to dampen ping/resonance on FK-2001 keyboards. I purchased this from eBay and the seller told me he cleaned the switches and keyboard, which look brand new and feel great. He also put some rubber grip padding under the PCB which explains why the sound is so nice compared to my other FK-2001 boards.

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Thanks again for the help! It’s great to have place with such knowledgeable and helpful people. Attached some pictures for reference.

[thefarside]

Final update. Switching the contact leaf only temporarily fixed the problem. I wound up still getting intermittent issues with the key not registering and ultimately decided to desolder the switch and replace it with a spare. With the switch out I’m going to disassemble the switch plate to see where the issue might be.

[Johnbo]

Does yours have the ctrl <> caps lock toggle switch? Mine does and I think that causes some issues with control key not registering sometimes, as usually toggling the switch a couple times will get it to start registering.

[thefarside]

Does yours have the ctrl <> caps lock toggle switch? Mine does and I think that causes some issues with control key not registering sometimes, as usually toggling the switch a couple times will get it to start registering.

I didn’t realize there was a toggle switch between those keys. Where do you find the toggle switch? So far I haven’t noticed an issue with the switch being replaced but you never know!

[Johnbo]

Mine's on the back right here. I think it may have only been the older ones that had the feature, but maybe someone with more knowledge can chime in.

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[thefarside]

Mine's on the back right here. I think it may have only been the older ones that had the feature, but maybe someone with more knowledge can chime in.

20220207_114405.jpg

Thanks I don’t have that sticker but I might have the dip switches. It never occurred to me to check under the little door

[Polecat]

Thanks I don’t have that sticker but I might have the dip switches. It never occurred to me to check under the little door

Johnbo is correct that only the early models had the Ctrl/CapsLock swap. The keycaps on those had the alternate legends on the front. The slide switch is on the upper edge as in the photo, labelled "Inverse<->Normal". The dipswitches behind the folding leg are for the different XT/AT modes. Some slightly later models had the notch(es) in the case, but no switch(es).

edit: another way to tighten up a Focus case here:

viewtopic.php?f=62&t=22072&p=446271

[thefarside]

Thanks I don’t have that sticker but I might have the dip switches. It never occurred to me to check under the little door

Johnbo is correct that only the early models had the Ctrl/CapsLock swap. The keycaps on those had the alternate legends on the front. The slide switch is on the upper edge as in the photo, labelled "Inverse<->Normal". The dipswitches behind the folding leg are for the different XT/AT modes. Some slightly later models had the notch(es) in the case, but no switch(es).

edit: another way to tighten up a Focus case here:

viewtopic.php?f=62&t=22072&p=446271

Thanks for sharing! That is quite the job you did on your black focus. I regret not buying a FK-2002 when I had the chance.

I like the relief put in to add screws to the front of the case. The case is the weakest part of a focus keyboard.

[Polecat]

Agreed that the Focus cases have issues. They were cheap aftermarket keyboards when they were new (yes, I was there) and with that in mind I really can't complain. I think I paid $45 for the black 2002 originally. I have the receipt here someplace. Adding the case screws completely changed the sound and feel of that keyboard. For the better. I really need to come up with some sort of rotation schedule. I've been using the industrial gray Monterey K104 almost exclusively since it arrived last year. I've learned a few things about the Focus keyboards since I wrote that up, so I guess I should update that thread just for the (permanent?) record.