Ergodox problem – 1 key fires whole row

[scyb3r]

I’m hoping the community can help me here. I just assembled my dox from the PCB kit provided by Falbatech (czerak). My problem is that the index finger on the home row for the left side fires every key in that row. That’s the only key giving me trouble, and it is consistent, from the second the keyboard is plugged in, anytime I hit “u” (since this is dvorak) it fires  “SHIFT + A + O + U + I”. I’m also using the Switch Hitter program to see what key presses are registered.

I have another dox that works fine, and I have confirmed that the problem is contained on the left side unit, since I tried my left side from my working dox with this new one and there was no issue.
I’ve tried using a multimeter to check the diodes on the left side, and everything seems to register fine. I’ve also tried following some of the steps found on this issue (https://geekhack.org/index.php?topic=69184.0) testing the MCP connectors to the switch connectors for the appropriate row/column. The continuity tests seem to pass – so I’m not sure how to solve this. –but I also admit that I’m no electronics maven – so I could be doing something wrong.

Specifically this seems to be coming from the SW3:9 key – or at least, that is the key that triggers this whole row behavior.

Also, as a side note, if I need to remove some switches what is a good way to desolder and remove the switch without breaking it? My last attempt at removing switches seemed pretty bad – does anyone have advice on that front? I use a desolder pump, but I can never get all of the solder out, so the switch doesn’t want to come out.

What can/should I do?

Thank you

[plegnic]

Also, as a side note, if I need to remove some switches what is a good way to desolder and remove the switch without breaking it? My last attempt at removing switches seemed pretty bad – does anyone have advice on that front? I use a desolder pump, but I can never get all of the solder out, so the switch doesn’t want to come out.

Get some solder wick. A desoldering pump is good for picking up big chunks of solder, but sometimes it can't get everything. Some people only use a wick, but I hate it so I only use it when I really need to.

As for the rest, it's hard to say. It sounds like you might have some kind of short. What specifically did you test with the multimeter? EDIT: oh just saw where you linked the test. I would get that switch out of there and test it by itself.

[scyb3r]

Thanks for the advice. I ordered a solder wick. I was also able to remove that one switch a put a new one in its place - but the problem remains. All other keys work fine, but when I hit SW3:9 it fires all keys in that row.

Do you have any tips on where I could look or what the issue is likely to be?

Thanks

[KHAANNN]

You're supposed to get the solder pump very close, it can even touch the soldering iron, it doesn't melt significantly to cause issues, if you watch some online videos, some people just push the desolder pump onto the iron

I have 3 soldering pumps, one is the cheapest kind, one is a good plastic one, one is a great metal one, the good plastic one is the best, as it's easy to re-use/reload, all of them pump better than that, but I'm guessing it's because you either don't heat the solder well, or keep the desolder pump too far away

Ideally, you should touch the solder for a second, it should get completely liquid, and you should pump it out in 1-2 tries, it gets better with time (it's 4-5 tries with some lead's)

I also noticed that Weller lead is much better than others, it gets soldered and de-soldered easily, some cheap ones stick to the board and keep resisting, stock ones are usually like these

So I suggest also buying a quality solder lead with built-in flux

[dorkvader]

Make sure you have all the diodes facing the right way on that column. It's hard to see from your pictures but SW3:9 looks correct. Not sure about the others though.

[scyb3r]

That was a good thought. I checked them just now, and everything in that row seems to be facing the correct way. At this point it seems that I need to key-by-key desolder the switches and diodes (and redo them) to see if that helps. Is that where you would start? I've also heard that the MCP/IO Expander may be the culprit, but the key by key for the row seems the lesser of evils for now. Would you agree?

Thanks

[tp4tissue]

it's possible.......

that the row is shorting because the solder made it's way onto the other side of the plate, and caused a short..

[Pandora]

II'm havinig kind of a similar problem in thhat when I hit some of thhe keys on the riight side they produce multiple letters. It doesn't happen all thhe time, but it's really annoyiing whhen it does. And sometimes it just stiicks a letter in whhere it doesn't belong.

 It's mostly the II, H, and UU keys.  Thhhe keyboard is a year and half old and I boughht it fully assembled. Does anybody have any idea what mighhth cause this?