Diode the wrong way around?
Is it in a metal case? Could be shorting...
hm... to me that also sounds like an diode issue... could you upload a picture of the soldered pcb? that could help
Yeah, that looks fine. You are going to have to take some measurements with a multi-meter. First would be to test the diode. It should have around ~600mV drop in one direction and seem open circuit in the other. Then you will have to check the row and column connection to both sides of the switch to make sure that they are sane with no shorts.
Okay, so I took the keyboard with me to work today. I have never used a multimeter, so I asked my hardware colleague for help. He did some measurements on it and concluded that the diode is not defective or the wrong way round. He suspects that I accidentally soldered two contacts together on the other side, but he wasn't sure himself. Unfortunately, he did the measurements rather quickly and I didn't take notes, so I don't know for sure what he measured. Maybe I'll have to do it again myself.
Regarding his theory: I just learned soldering during this build, so it's absolutely possible that I messed it up somewhere. But I know I did a rather thorough visual examination after soldering it and didn't see anything suspicious. Just taking a look isn't easily done: if I'm not mistaken, I would have to de-solder and take out all the switches, which (given my lack of experience) might introduce other potential failures if done wrong. I wouldn't even know how to do this properly; I guess I'd have to alternate with the soldering iron between both contacts of a switch to warm them at the 'same' time and then quickly pull the switch out?
What would you recommend?
Another option might be to re-program the QMK firmware so that it puts out a '1' whenever '1qaz' is pressed. But I don't know if that's possible, and it's certainly not the most elegant solution.
I tried to de-solder the switch in question. I did a very bad job and I think I destroyed the switch in the process. Well, I ordered two spares so it's not a big deal. Anyway, with the switch out of the way, I tried to have a look at the diode solder joints on the other side of the PCB. They looked OK, but maybe one of them overlaps a little with this other thing on the PCB (I don't know what it is). In the picture, I have circled the diode contact in question and the thing that it might now have contact with:Show Image(http://i65.tinypic.com/2epscw6.jpg)