ErgoDox left hand not working

[Batty]

I'm working on de-soldering all the switches from my vanilla ergodox so I can move them to a falbatech full-hand case.  I finished removing all the keycaps from the left hand and re-soldered them with the new switch plate, and everything tested out good when I reconnected the two boards together.  I moved on to the right hand, and I've just finished re-soldering everything, but when I reconnect them, the right hand works, but now the left hand doesn't!  Can anybody offer some advice on how to troubleshoot what could be going on here?

The only thing I could think to try was re-flowing all the joints for the 3.5mm connector on the right hand in case I accidentally damaged something there, but that yielded no results, unfortunately

[tp4tissue]

that's odd, multimeter the connection to ensure the 3.5mm isn't broken at the connector sockets.  so meter down the line, don't meter the pins on the connector.

[Batty]

Thanks for the advice!  I'm a total rookie with my multimeter and have only used to verify a wall socket was active, can you point me towards a resource for how to test this connection? 

[tp4tissue]

There should be a diode setting (diode symbol, triangle and a line) where if you put the two tester together it beeps.

When it beeps that means the 2 points are connected.

If there is no diode setting.. Change it to the resistance setting (any of them) with the Ohms (omega symbol)

Under this setting when you put the two testers together, the reading will be Zero(0).  That also indicates the 2 points measured are connected.


The trrs has 4 pins.

Measure some where down the line, means following the traces up (the copper leads) after the connector.

You can't test the trace themselves because it's under lacquer, look for open copper pads or junctions, test along the road..

Make sure the connector makes it into the board.


So, one test lead on one of the Tip Ring Ring or Sleeve..  then make sure that goes where it needs to go INTO the pcb, keep following it into the pcb.

You don't need to follow it all the way,  just around past where you did your soldering, where it may have been disturbed.

[Batty]

So I think I successfully tested across the 3.5mm connector between the two boards.  I flipped them both over and tested from the through-hole pins on each connector where it was soldered to the board, and was able to verify connectivity while I had the cable connecting them.  Frustratingly, I re-soldered the left 3.5mm connector, tested, and it worked!  Upon re-assembling the board into the case, however, it suddenly stopped and I was no longer able to get it working.  I even removed a 3.5mm connector from my other dox and soldered it in and that didn't work either(though I noticed that this connector from my massdrop order had only 4 pins while the one I got from falbatech had 5, this shouldn't matter, right?)

I'll try following and testing some of the traces when I get home tonight, I didn't have time last night.

[tp4tissue]

Those 3.5mm trrs jacks are notoriously low quality.

They broke on both my ergodoxi.. And I plug/unplugged the cable no more than 25 times.

I have my cable soldered directly to both halves..


It seems like that's what you're experiencing as well..

 My recommendation is to solder the cable direct to board,  Then put a dab of hot glue to hold it down / strain relief.

[Batty]

Well, I re-soldered all my joints on all my key switches and in the process found what looked like a bad diode.  After removing it, I found the left hand was working correctly.

I'm not sure what the issue was, or if it's even possible for a bad diode to take out the whole board?  I'm just happy it works now...thanks for your assistance in walking me through troubleshooting the 3.5mm connector!