Berlin: Keyboard repairs?

[Canut]

Hi all,

I hope this is in the right section.
I need help with two keyboards: Diagnosis and repair. I'm in Berlin, Germany. Can anyone help?

1. Ergodox. I use this all day every day, for my work. I was being a bit rough with it yesterday (yes, I'm an idiot). Now, the lower-right key doesn't work (dead switch? damaged diode? cracked PCB trace? I have no idea). I have the arrow keys mapped to this bottom-corner area, and they are vital for my work. So fixing this is a priority. I have spare Cherry switches, but I fear it could be more complex than that.

2. Matias (mini tactile pro). The left Ctrl keys only works intermittently. It's been like this forever. If the Ctrl fails to trigger as part of a key combination, it causes chaos with my work.

Re-mapping left Ctrl onto Caps Lock solves the problem. However, I don't use the keyboard much, so I would prefer to fix it and sell it. I have spare Matias switches.

Anyone? I'm happy to pay. But I rely on the Ergodox for my job, so I would prefer someone who's confident with this stuff.
Any suggestions are highly appreciated.

Thanks!!

[Wodan]

got a multimeter?
most common reason I had for key failures was broken diodes ...

[Canut]

I do, but I have no real idea how to use it.

Not sure whether I did this correctly, but:
Touching the multimeter probes to the switch pads and then the diode pads changes the reading and gives an audible beep. The numbers (resistance?) are the same for the "broken" switch and the functioning ones.

[Wodan]

try measuring both sides of the diode. and then measaure the other way around by swapping the red and black tip.
one way should "beep" meaning the diode still let's signals through.

if you can't get a beep across the diode no matter which test lead you put on what side, your diode it broken.

[Canut]

[edit]
I presumed that I would get a reading by touching the probes across "opposing" PCB pads (i.e., from one side of the diode / switch to the other). But that does nothing on the multimeter, even with the functioning keys.

So I touched the bits that are close to each other (i.e., the PCB pad on one end of the switch with the adjacent solder blob on the same end of the switch).

That seemed counter-intuitive (like I'm just touching two parts of the same thing, rather than actually "bridging" the probes across the switch or circuit). But all the functioning switches / diodes gave a reading using that method, so I simply repeated it with the known problematic switch.

I don't have a huge amount of time to pursue this today (chasing a deadline that needs to be in Japan by early tomorrow morning ). But please keep the tips coming; I'll check back here as soon as I can.

Thanks again!

[Wodan]

take a picture of your multimeter and one of the pcb section that is affected. I'll draw circles around things - much easier than explaining stuff here.

[Canut]

Will do; thank you very much.
But it won't be before tomorrow morning (German time), due to work pressure.

Thanks