Ergodox issue - teensy operational, soldering fine, but no keystrokes

[janislaw]

Hi,

I'm a happy user of Ergodox. I received it assembled with a decent quality. I only had occasional issues on TRRS jack, which required unpluging and plugging it in.

Now the keyboard stopped working. Here's what I've checked (on the teensy half, I've didn't check the other one):

- teensy uploader works with both connectors
- after bootloader button is pressed, the device presents itself as "Bus 003 Device 015: ID 16c0:0478 VOTI Teensy Halfkay Bootloader", after power cycle it's not listed in lsusb, I'm not sure if it should
- I found no obvious shorts or breaks between traces, the soldering looks good to me, however I can post a photo

Please help me troubleshoot the keyboard, do you have any ideas what to check next?

[tricheboars]

post photos if you want help. if you want help quickly from me (who has an ergodox and built more than one) upload your images to something other than imgur since i cant see images from that site at work. otherwise i will look at anything uploaded after work. 

take photos of both sides of the teensy.  take photos of the resistors, diodes, switch joints, everything.  from what you are describing i am inclined to think there are some bad solder joints somewhere. but we cant really help until we see your work.

[janislaw]

Hello,

Thanks for the quick reply. I've uploaded the photos here: https://drive.google.com/folderview?id=0B7sHRYxLA1qCcVJFWURzcGlpd28&usp=sharing

I hope they're sharp enough, I don't have a macro lens at hand.

[tricheboars]

my thoughts:

-i see what could be several cold joints on your key switch soldering. also i would add some solder to the teensy d3 joint and gnd.  i would add some heat and a dab of solder to your teensy and i/o expander. i mean just a tiny little bit to get the flux/solder flowin.

-i dont think your diodes are on the right side. i used SMD instead of through hole so i could be wrong... not sure. flags were raised.

-i would clean up the excess copper on your usb connection/cable.  my fear would be that could cause a short or some kind of issue with the joints underneath it.

what kind of solder are you using? 
what temp is your iron set to?

[janislaw]

Thanks for the soldering review. I have received the board already assembled, so I can't tell about the solder and the temperature. I can do the reworking as you suggested and recheck everything.

Re diodes: the keyboard was working well for two months, so I'd rule out diodes. The diodes cathodes are are soldered to the square pad, so I guess any side is ok. If I were to assemble it from scratch, I'd go with SMD as well, I hate clipping.

[Larken]

soldering looks fine to me.

unplug the trrs cable from the right hand side, then plug the usb cable in. check if the keystrokes on the single right hand side registers when you hit them.

if yes, then it is likely a problem with the trrs cable/ports. I'd try another cable - and if that fails, unsolder the trrs ports and hardwire the two halves together.

[janislaw]

In the meantime I soldered another Ergodox, learning a little about the circuitry.

I've checked the left hand of the old one plugging it to the new one - it works well.

I've applied the soldering iron to teensy, TRRS and USB and separated the wires from the short USB so as they don't short. That did not help: when I plug in the keyboard (right hand only) no keystrokes are produced, however the teensy seems programmable. I've also shortened the row and column pins manually while the keyboard was attached - still no keystrokes.

I consider the keyboard hardware OK and teensy board problematic. What are your thoughts? 

[tricheboars]

replace the teensy outright.